If you mean that little mp3 flash player (which can be plugged into USB port) - I have that one. Pretty useful on boring lectures in university.
I have 256 MB, but that's enough. Loading whole damn playlist into player with 10 GB of memory is sort of self expression. I have only about dozen of hits every month, so, like I said, 256 Mb is more than enough.
More than that, that player comes like another USB storage device, if you need to get something and don't have your flash drive, so that doubles the usefulness.