Bought this elsewhere with the intention of using it with the Readyboost function that Windows Vista and 7 have (specifically for a Acer Aspire Revo 3600 nettop). The drive has a silicone (I think) skin and loop with a choice of 3 coloured caps for the USB plug. It is tiny: about half the length of a typical USB drive and so does not take any space from the adjoining USB ports on a nettop. And when plugged in, it protrudes by 2 cms. However, the Vista system on the nettop (yes, I know: I'll get round to removing it at some point!) refused to allow its use for Readyboost (saying it 'did not support the Readyboost requirements' or words to that effect).
This was somewhat disappointing, particularly as the packaging indicated its compatibility with Vista and Readyboost. So I tried it in a self-built Windows 7 PC, which recognized it immediately and was happy to use it for Readyboost: I don't know if it was something with the Windows Vista operating system or the Acer Aspire Revo 3600 nettop that prevented its use. It worked out OK in the end as I instead plugged the drive into a newly acquired Blu-ray player to enable the BD-live function - it barely protrudes beyond the back of the Blu-ray player and is working nicely there at the moment.
Just a couple of caveats for any purchasers. When operating it has no LED to indicate it is working so there is the risk of removing the drive during operation unless you dutifully use the 'Safely Remove Hardware' procedure in Windows. And as I mentioned it's tiny: I removed the metal lanyard initially but re-attached it afterwards as, with my large fingers, there was no other way of pulling it out of a USB socket (particularly if it's surrounded by occupied USB ports).