ActiveWin has posted up a review of 3 Windows Vista capable ReadyBoost USB sticks.
We have been running a number of Windows ReadyBoost tests on various USB Drive Sticks that have come out recently. Not only do we have a list of those that work, and those that don"t! We have also started to go in-depth with some of them. ReadyBoost is designed to improve small random I/O for people who lack the expansion slots, money, and or technical expertise to add additional RAM. This isn"t a replacement for RAM upgrades; it"s simply the chance to speed up your Vista machine very slightly and very easily.