Sync Your Phone to Your PC and the Web with Microsoft Phone Data Manager
Microsoft's Phone Data Manager syncs your contacts to the Web and downloads music, photos, and videos to your PC. What's interesting is that it's designed not for Windows Mobile phones (which already have these sync capabilities), but for non-Windows Mobile phones.
The Windows-only app pairs with your cell via USB (BYO cable) or Bluetooth. Once the connection is made, the software ferries your phone book to your Windows Live Contacts account (which is tied to your Windows Live Hotmail account), thus giving you an online-accessible backup of all your contacts. At the same time, it can copy the aforementioned media files from your phone to your PC.
PDM has been tested with a few dozen phones, mostly models from Motorola, Nokia, and Sony Ericsson. It's currently in beta and not a supported product; my guess is it's a kind of working preview of a feature that'll appear in Windows 7. Alas, I don't have a supported phone, so I can't put it to the test. If you can, report your results in the Comments! [via Paul Thurrott's SuperSite Blog]