Tracking a stolen iPod touch

Background: My iPod touch was stolen while I was at school. (I'm in High School, btw.)

I already tried looking for it using Find my iPhone, to no avail. Find my iPhone is a useless service for Wi-Fi devices as the iPod will only connect to Wi-Fi hotspots it already knows. Since my iPod was locked w/a passcode, it's unlikely it will join a network. I'm going to assume that the person who stole it wiped it by now and sold it...

Is there any other way I can track it? (Maybe something that Apple at the Genius Bars can do?)