Check out Altec Lansing's line of portable iPod speakers. I have the T612 model, though that's a bit out of your price range at $130. And you need an outlet source. But they have several more portable model types available ranging from about 35-80. The sound quality of mine is quite good. Most iPod docks (though not all) have an input where you can plug in a non-iPod mp3 player, though you'll want to check the item info for that.