smallest and most mem you can get. The new IPOD shuffles are nice and small, but I picked up a Samsung 1gb last xmas and wear it on a lanyard around my neck.
CD players are a joke........
Also you can compress the songs, to fit 3-4 times more songs on 1GB then advertised. You loss a bit of sound quality and bass but nothing to complain about. I'd rather have 400 song on my 1gb then 130 songs. It makes a differance when you're on a all day ride.