If you really want to hear the music on an iPod, then also buy a good pair of headphones. I prefer ones that are designed to block-out surrounding noise, which is nice when you travel.
http://www.etymotic.com/ephp/er4-wrfy.asp I recommend the ER-4P or the 6i models for use under a helmet, not that I would condone wearing them while riding
I just ordered an iPod shuffle but there's a four week wait for delivery.