Hey everyone, this may be old news to a few of you, but I hope it helps a couple of you.
A point of note is that SD cards don’t work for some reason. At least my ‘ultra’ and Class 6 SDHC don’t… haven’t worked out why, perhaps yours would?. But anyway, you right click on your usb in your computer in windows explorer (the normal file browser, not internet explorer), and go to properties. Then you have a tab at the top called ‘readyboost’.
ReadyBoost on Vista does work with SD and MicroSD(HC) cards just fine. For microsd just use a SD adapter. Prices are low nowadays so shop around and find yourself a cheap boost 🙂