In the various motorcycle magazines there are mp3 player holders and such that will allow you to mount them on bikes. I've also seeen speakers that can mount on handlebars (they look ugly, in my opinion). The Apple iPod is a good mp3 device that has a large hard disc and good interface; you might check into that one.

And oh, I forgot, Triumphs are the ones that drip oil. Harleys are the ones that shake all the bolts out of their engines onto the road.

(Don't take this seriously, I'm a biker too)