Steal it back. Simple as that. Its yours, not anyone elses, when you steal it, confirm its yours, if not, give it back saying you found it somewhere.
I did it before when i was in 7th grade, not an ipod though, my bike, someone stole it took off the stickers and all that crap, went to school in the morning found it in the bike rack, took it out rode it home, and came back to school late, it was worth it. :3
aha general consensus is to beat him and steal it back. Well i've been good friends with his girlfriend for about 5 years now and she's not aware of the situation..so i texted her about it. I should get it back..if not her brother has offered to give me his old 30GB ipod classic to compensate for it.