Hmmm... we have a 4gig Hitachi microdrive at work. Will have to borrow it tomorrow and test over the weekend. Part of our product runs on mobile devices (palm, trio, midp, etc) and in theory the storage medium is abstracted from the software that writes to it. So a Microdrive should not respond any differently (other than speed) than a CF, or SD or any other type of supported card.