I bought a 2GB Apacer Handi-Steno HT-203 (supposedly the fastest) USB stick for my 2GB RAM Vista Ultimate PC w/2 WD 10K RPM Raptor HDDs and try as hard as I could , so as to justify the time and expense, I didn't notice an improvement in speed. I did see that the LED on the USB stick was flickering most all the time, lots of activity, but no sense of immediate refreshing of anything I had been working on.
I now use the Apacer for an emergency backup our web sites so I'm OK with the purchase.
It configures itself when you plug it in with a simple, "YES use for Ready Boost," and it can easily be reconfigured to use as a regular USB HDD.
Your experience may vary.
Kerry