sailfish
Master of Karate and Friendship for Everyone
I actually got a pretty good speaker that I do that with now. I'd like to get my hands on something with its own radio though.Someone mentioned the sharkk
There is a place to plug in an accessory cable. Take your mp3 and plug it into the Sharkk(or any other small mobile boombox) and you are good to go.
The sharkk battery lasts all day. Good sound and good quality.