I've spent a lot of time trying to figure out personal information management (PIM) synchronization over the years. There were the dozen or so PDAs I've used, including the first ever Windows CE-based device, a NEC Handheld PC (HPC), various Palm OS-based devices, numerous Windows Mobile variants, a cool credit card sized device called the REX, and a Timex data watch. (I know, I know, look at the geek.) When I began my experiments with Mac OS X in 2001 (you know, several years before today's trendier tech pundits), cross-platform data synchronization became an even bigger issue. In fact, it never really got easy or seamless, despite various attempts by companies like Apple, Palm, and others to make it so.

Much more recently, I've been experimenting with various email and PIM cloud platforms, all of which offer some level of data synchronization across the Web, local PC applications, and mobile devices. The result is my multi-part Managing Your Life in the Clouds series, which came about after a disappointing but promising experience with Apple's MobileMe (see my review). Critics have called it MobileMess, which it is, but Apple's clearly onto something. And as is so often the case with data that was traditionally stored on a single PC somewhere, your PIM data wants to be free. You should be able to access, manage, and change it from wherever you want, whenever you want.

That seamless future is still, alas, in the future. But I was surprised to discover recently, thanks to reader Prakhar Bahuguna, that there is an obscure and largely undocumented feature in Windows Live Messenger, Microsoft's consumer-oriented instant messaging (IM) solution, which allows users who have bought into the Windows Live experience to pretty seamlessly synchronize their contacts across an unprecedented number of end points, including, ultimately, even Apple's iPhone. This was, to my knowledge, not possible before, or I should say not known to be possible. And if you are storing your personal information in Microsoft's Live service, your options are much better than previously believed.

Where this began

This integration dates back to mid-2006, when Microsoft launched the first version of Windows Live Messenger, the successor to Windows Messenger and MSN Messenger (see my review). At this time, the software giant implemented Messenger integration with the Windows Live Contacts service. Think about how this works: When you sign up for Hotmail or other Windows Live services, you get a Windows Live ID, or what used to be called a Passport account. This WLID binds your various Windows Live experiences together, via different integration points, but also by consolidated back-end services. So starting with the release of Windows Live Messenger, your contacts list in Messenger was integrated with your contacts list in Hotmail. The underlying database that stores these contacts is Windows Live Contacts.

What's interesting about this integration is that your WL-based contacts can now be managed via a number of places. Some of these include:

Windows Live Contacts. If you navigate directly to contacts.live.com, you'll be brought to the Contacts UI inside of Windows Live Hotmail, or what you might think of as the Web-based version of Windows Live Contacts. This Web version, incidentally, has some unique functionality that you may find beneficial. One of these features is contacts merging, which is especially nice if you, like I, have overlapping contacts that previously existed separately in your email and IM applications.

Windows Live Messenger. As noted previously, your Windows Live-based contacts will also appear inside the main window of Windows Live Messenger. (You can alternatively turn off the display of non-Messenger contacts, which might be advisable if you have a lot of "traditional," contacts who aren't on Messenger.) Using this applications, you can actually trigger new emails to these non-Messenger contacts, start IP-based phone calls, and perform other related actions.

Windows Live Mail. Microsoft's free email application for Windows XP and Vista includes Windows Live Contacts integration as well: Click on the Contacts link in the Shortcuts pane and a separate window, logically called Windows Live Contacts, will appear. You'll see a number of Live Contacts-specific features here, including each contact 's customized display picture (if configured).

Outlook 2003 or 2007 with Outlook Connector. Users of Microsoft Outlook can install the free Outlook Connector software, which provides Exchange-like access to one or more Live accounts. Each account will have its own email, contacts, and, in the latest Connector beta, calendar(s). In the Contacts UI in Outlook, you'll see the local contacts list, but also a separate entry (in the form of Contacts in username@live.com) for each Live account. That listing will match up with the contacts list you see in all the other listed solutions.

Windows Mobile. If you synchronize with a Windows Mobile device, you can also see and manage your Windows Live Contacts list from within the native Contacts application on the device. Microsoft has also created a native Windows Live for Mobile application with access to Windows Live Hotmail, Messenger, Spaces, and Search. (You can of course access Windows Live Contacts and these other services via the mobile Web as well.)

That's not too shabby of a list, and I'm not even including native support for a few other mobile platforms, including the Blackberry and some Nokia devices. But one of the sticking points with cross-platform sync and Windows Live Contacts is that there didn't appear to be a way to automatically between the service and Apple's innovative iPhone.

As it turns out, this is indeed possible.

Overcoming that final hurdle

Given that Apple natively supports Microsoft Outlook for email, contacts, and calendar sync, you would be forgiven for thinking that this would be the logical outlet for getting data from various Windows Live services onto the iPhone. And believe me, I've tried. I don't believe it's possible. Here's what I do know.

Yes, you can actually change a Windows Live account to be the default account in Microsoft Outlook. You do so by visiting Tools, Account Settings and then the Data Files tab in the Account Settings dialog. If you select your Windows Live account (typically named username@live.com) and click the Set as Default button, you will see your Windows Live account data by default when you click the Mail, Calendar, Contacts, or Tasks shortcut buttons in Outlook. And if your Windows Live account is your main email account, or your only email account, you may want to do just this.

There's just one problem. If you do this, you cannot sync this information with the iPhone (or, as it turns out, Mobile Me). According to Apple's documentation, the iPhone can only sync with a Unicode formatted PST (personal storage) file. The thing is, Live accounts configured through the Outlook Connector don't use PST files at all, Unicode or otherwise. They use OST (offline storage) files, as does Exchange. This makes sense: As with Exchange, the data is stored in the cloud, but is synced (and cached) to the client.

So Outlook is out. Why is fine with me, frankly, since Outlook is expensive. Wouldn't it be nice if you could sync your Windows Live Contacts data with a free application (preferably one that comes with Windows) and then sync that information to the iPhone?

The trick to making this happen is to use Windows Vista and Windows Live Messenger, the latter of which is, again, one of many outlets for managing Windows Live Contacts information. Once you've installed Windows Live Messenger and logged onto your Windows Live ID account, open up the main application window and choose Tools then Options to access its Options dialog. On the Security tab, there is an option titled, "Encrypt contact list data so that it is not accessible outside of Windows Live Messenger." The option is checked (selected) by default, so un-check it. Then click OK to close the window.

When you do, open Windows Contacts in Windows Vista. You'll see a new folder with the name of your Live ID (in the form of username@live.com). Inside this folder, eventually, will be all of your contacts, completely synced up. (It may take a while depending on the speed of your connection and how many contacts you have.) Here's what kills me about this. It was actually pretty well documented over a year ago. In fact, it was even posted to the Windows Experience Blog last May.

Now that your contacts are synced between the Windows Live cloud and Windows Contacts in Windows Vista, here's what you can do:

Sync your Windows Live Contacts to the iPhone (or MobileMe). Apple's limited sync software works fine with Windows Contacts. Any changes you make on the iPhone are synced back to Windows Contacts and thus to the cloud. (Eventually. OTA support would be even better of course.)

Make changes to your Windows Live Contacts from anywhere you want and watch them sync up. You can manage your contacts from any of the solutions listed above. Or from Windows Contacts. Or from the iPhone. (Or from MobileMe if you sync that way too.) It's up to you. Any changes you make will be synced all around, and automatically, though I should warn you it's not immediately. Eventually, what you will see is the same consolidated view of your contacts from any of the Windows Live Contacts-compatible solutions discussed in this article.

A few final tips

Contacts syncing through the Windows Live cloud isn't immediate, as warned, so don't freak out if you've deleted a few contacts in, say, Windows Contacts and you're wondering why the changes haven't replicated up to Windows Live Contacts on the Web. They will. Just give it time.

You can (and should) backup your Windows Live Contacts by copying (not moving) that new folder out of Windows Contacts. That way, if you make any mistakes later, you can go back and fix the errant contacts.

Also, as noted previously, you may be surprised to discover multiple duplicate contacts in your Windows Live Contacts list. Many of these duplicates probably occurred last year when Microsoft consolidated your Messenger-based contacts with your Hotmail-based contacts. (This was certainly the case with me.) To fix this, access Windows Live Contacts via the Web and choose Clean up duplicate contacts from the Options menu. (Also, I recommend enabling the option "receive contact updates from this person" for each of your Messsenger-based contacts. That way, any changes they make to their profile--like a new cell phone number--will automatically appear in your own contacts for that person.)

There's more to be done

In my recent explorations of getting Windows Live data synced across as many usage points as possible, I had pretty much reached the point where I believed that true sync with the iPhone, especially, was impossible. But, as I've documented here, you can in fact get it to work if you know the trick. It's not complete: While it's possible to segregate contacts into Groups on Windows Live Calendar, these groups are not populated correctly when the data gets to the iPhone. Maybe that will happen someday.

What's also not possible, of course, is to access Windows Live Hotmail from the iPhone Mail application. And native calendar sync between Windows Live Calendar (which, admittedly, is stil in a pretty precarious state) and the iPhone's native Calendar application isn't happening ... yet. I'll keep looking. But in the meantime, I'm happy to be able to at least get my contacts back and forth between two of my favorite contacts management systems, Windows Live Contacts and the iPhone.

Again, thanks to Prakhar Bahuguna for the tip.