Readyboost! Got an extra USB Key?

So I have heard the readyboost concept in Vista, but I had never actually tried it out. Basically, it uses extra memory (like a usb key) to help speed performance of your Vista PC without upgrading the internal RAM. 
Check out this Channel 9 Interview with Michael Fortin.

http://channel9.msdn.com/showpost.aspx?postid=242429

I’d like to test to see if this can help our demo machines speed up a bit even though they are maxed out at 4GB RAM each.