Got mine today. Definitely not iSight quality, but pretty good for $35. It came with an Xbox headset, which is great if you want to start your own call center. The image is quite grainy, especially in low-light circumstances. It has very colorful pixelation in dark areas. It also has this weird vertical wave going on, kind of like when you seen an old CRT monitor in a movie; the wave gets worse if connected through a USB hub. But it's probably 95% as good as an iSight. The focus ring is manual and works quite well, and the ring around the camera glows green when it's activated and it's not laser-bright, which is nice. It has a rubber anti-skid square ring on the bottom and the camera is attached to the base by a friction ball pivot, so you can angle it pretty easily.
Pros:
90% as good as an iSight
Cheap ($35 shipped)
Really long cord
Small and white; aesthetics match Mac stuff
Cons:
No onboard mic
Manual focus ring
Picture quality somewhat grainy
Weird wave pattern
I also picked up a high-end Logitech webcam for I think $50 AR for my other Mac, so I'll see how that compares when it shows up. Bottom line, if you need a pretty good cheap mic and have separate audio, this is your ticket.