I've got a couple of the 1GB that I use strictly for Readyboost...so, I can confirm that they work.
I wish this would have been posted a week earlier. I bought a three pack of the Cruzer Minis for around the same price on eBay for the computers at the office...still haven't gotten them! I coulda just went out to OM and gotten these today. Well, maybe they'll come in the mail today.