Great idea on how to share some music and expand your library.
"HOW TO PLAY IPOD WARRead the link for the rest of the rules.
The object of the game is to put your music library up against another person's - find out some secret favorites they have, and hope your guilty pleasures don't pop up in an embarassing number.
Playing is simple: In the card game WAR, two opponents split a deck of cards. In each 'battle,' players would turn over the top card on his or her deck. Whoever had the highest card won the battle and kept the two cards. At the end of the deck, the person with the most cards won the war.
iPod War follows the same guidelines. Two people put their iPods on Shuffle and play music. As each song comes up, whoever has the better song wins the battle. After 10 songs, the person who won the most battles wins the war.
It's not necessary to play iPod war in person (I typically play over instant messenger)."