As far as I know, there isn’t a warranty that covers your I Pod Touch if it has been lost or stolen. Where did you lose it? I found someone’s MP3 player in the marketplace on my campus and turned it over to the Lost and Found. So if I lost something, I’d first check my person (it might be in a pocket.) Then I would retrace my steps: Where have I been? When was I last conscious of having it out? If it’s not where I left it, then I’d check the nearest Lost and Found.
Depending on where you lose it, you’re probably not going to get it back.