DoubleTwist, the file-sharing, media-organizing, device-syncing software project from DVD Jon was previously only available for Mac. Now they've opened the beta up to Windows users, which I'm sure will bring in a lot more downloads.
For those unfamiliar, DoubleTwist promises compatibility with most personal, consumer electronic devices, including mobile phones, cameras, camcorders and MP3 players, for sync and management capability. Plus, they're constantly working to not only update the database of supported devices, but also the features within the software itself. You can also add friends who are also using the app to swap and stream files freely.