I finally got around to installing and testing out Silverback tonight. Silverback is a nifty Mac gadget that does picture-in-picture screen capture, i.e. exactly the application you want for your guerilla usability testing lab.
What I don’t understand is why I haven’t heard people raving about this. There is the obvious drawback that it only works on a Mac with built in iSight, but we’re not too small a percentage of the broader design community. Is it just that people don’t know about this product, or is there some catch I haven’t yet experienced?