I wrote this as a small side project to teach myself Flash/Actionscript, which was quite, um, interesting, given my C++ background (I miss static type checking). It was a lot of fun though, and I owe many thanks to our UX designers who helped supply the necessary "Googley" factor.
You can try it out here in the Google Talk gadget - simply click on your Google Talk picture in the upper right hand corner, and choose the "Take Photo..." option (you'll need a webcam to see this option). You can also see how it works (in Japanese) in this unofficial video.
There are a few undocumented keyboard shortcuts for this feature:
will take a picture ESC will discard the taken picture ENTER will save it as your Google Talk picture