Do what i did.

Dont go out and buy another expensive MP3 player.

If you have got an exsisting PSP console, just get a larger memory stick for it. The largest one on the market is 16GB at the moment, and Sony will be releasing the 32GB memory stick Duo later on in this year.

Best thing with the PSP is that with that space you have, you can do just more than just a collection of music tracks, but movies, photo albums, applications, and the great gaming catalogue that the Playstation Portable has to offer, including Pure (Which is now at Platinum price), and awesome Pulse.