Personal advice: Go down to Adelphi and look for Jaben. Somewhere on the top floor I think. Get the Crossroads earphones, whichever model they have and you like. It is cheap, excellent, and the post-sales service you receive there is unmatched.
Also go get the in-ear foam pads. It blocks out practically everything from the outside so even if your ipod is on low volume, you can hear everything clearly and crisply.