This this is interesting. Since fairly early in the Windows Vista beta, Microsoft has been touting a Vista feature called Windows SideShow, but the required hardware has never really appeared in any mass market product, though the odd laptop with an external SideShow display or Sideshow-based remote control has popped-up on occasion. Now, with this new software, you can use your Windows Mobile 5- or 6-based smart phone as a SideShow device...

Brief Description

Windows SideShow for Windows Mobile is an application for Windows Mobile 5 and 6 PocketPCs and Smartphones that allows you to use your Windows Mobile device as a Bluetooth SideShow device. Installation instructions are below. This is a beta release.

Overview

Windows SideShow for Windows Mobile is an application for Windows Mobile 5 and Windows Mobile 6 Pocket PCs and Smartphones that allows you to use your Windows Mobile device as a Bluetooth SideShow-compatible device. This enables you to use your phone as an extra window into your PC. You can both access your computer’s information from your Pocket PC or Smartphone, and control the computer through a gadget interface. While the phone is out of range, or when your computer is off, you can continue to view content sent to the phone previously. This makes it easy to send information to the phone that you'll need later on.
The developer preview is an English-only release.

BTW: I once imagined a potentially viable use for SideShow. Picture a typical widescreen display and how the Windows Sidebar runs down either side of the display in Vista. With a SideShow-enabled monitor, you could have an extra LCD-based SideShow "strip" running down one side of the screen and instead of using the Sidebar, you could use this SideShow strip to display notifications. It might look something like this:

I suppose the strip could be removable so you could clip it to either side of the screen. On a laptop, this display might be visible when the lid was closed, such that the lid only covered the many screen. That way, the SideShow strip would always be available to alert you to new emails, show the time, etc.

Just an idea.