I'd recommend an mp3 player with built in radio and SD card memory slot. They're TONS cheaper than an IPOD Nano, more versatile, most run on a single AAA battery, and you can add more memory. (You can find 2 GB SD cards for < $20!)
The two that I have personal experience with are:
Sandisk Sansa e130: Loved the player, nice interface integrates the expanded memory well (the SD card) and sounds GREAT. It also came with the BEST ear-bud type headphones I've ever used. BUT: For some reason a week and a half ago it just quit working. I was sitting on the bus listening to it and it just died. Didn't drop it or anything. It was over a year old, but had fairly light use till the past few weeks when I started carrying it to work. The player DID get dropped into a full bathtub once, a couple months ago... I dried it out and it worked fine, but this COULD conceivably be a result of it's dunking.
Coby MPC751: I picked this one up cheap. Had it for about 9 months with nearly daily trips. Very rugged and has held up despite multiple crashes where it got banged. Cons: doesn't integrate the expanded memory as well as the sandisk. If you're listening to mp3's in the main memory, it can remember exactly what song and where in the song you were if you stop it or shut it off. If you shut it off while listening to music on the sd card, it defaults back to the last thing you listened to in the main memory. Sound quality isn't quite as pleasant as the Sandisk, but it's acceptable. I hated the headphones that came with it, and promptly 'stole' the headphones from my wife's Sandisk.
Bottom line: Both of these players are small and versatile. They both work well, and I'd buy another of either of them. Shopping for another Sansa right now, in fact.
You can get a 1GB Sansa e140 for about $80, throw in a 2GB card, and have a 3 GB player with FM radio for around $100.
Sandisk also has a couple higher-end players
(like this) that have a lot more memory (up to 8GB), and can display photos and small videos for less than $300, I'd get one of those in a second if I had the money.
edit: Hrmm... the e260 and e280 use a built in battery... I think I'd stick with one of the others for touring. Plus it's less loss if it gets lost/broken/stolen.