doubleTwist:

doubleTwist desktop enables you to easily share media with friends and sync with popular devices.

doubleTwist’s mission is to enable consumers to enjoy their digital media on the widest possible range of devices. Although the explosive adoption of CE devices has enabled any consumer to create and consume digital media, the process of sharing and moving media between the desktop and various devices such as mobile phones, gaming platforms and set-top boxes has become increasingly painful. doubleTwist is addressing this pain point by empowering consumers to easily share, consume and sync audio, video and photos regardless of device, file format or social network.

The initial doubleTwist product offerings include doubleTwist desktop, an application featuring an intuitive interface for sharing, consuming and syncing personal media; and “Twist me!," a social network application that allows users to share media directly from their profile pages. The beta release enables consumers to share media with their Facebook friends and provides sync support for the Sony PSP, Nokia N Series, Sony Ericsson Walkman & Cybershot phones, LG Viewty, and Windows Mobile smartphones such as those from HTC and Palm. Apple iPhone users will soon be able to view content they receive from friends by accessing doubleTwist from their phone’s Safari browser.

The desktop application, which currently works on Windows XP or Vista, is available as a free download at www.doubletwist.com.

I'm not sure what to make of this yet. But the big deal here is this bit, from their FAQ:

doubleTwist can automatically convert music you have purchased from the iTunes store to MP3, a universal format supported by all devices that play digital music. doubleTwist does not delete or move the original files.

You can only convert files that you have legally purchased and are authorized to play with iTunes.
OK. But what about video? And how is the conversion done, electronically or via an analog hole? Interesting, but I suspect Apple will shut this down pretty quickly.