A rebuilt raspbmc kernel with support for the Fushicai Easycap usb grabber (ID 1b71:3002). All credit goes to Sam Nazarko for his brilliant work. Sam, if you can see this, I would appreciate it if you included this module into the next release of Raspbmc :)
Please refer to the wiki for installation instructions.
All credit goes to Sam Nazarko for the brilliant raspbmc, and all the brilliant people who work on the raspbian and debian kernels - you guys rock!