How do I reboot my iPod?

My iPod keeps freezing. Just now it skipped on a song and froze (I didn't knock it or anything its sitting behind my keyboard on my desk. Its gone back to the 'Music' screen but its all misaligned ( the > for each section is in the middle of the screen) and its still not responding. Its a 4th gen that I bought 2 years ago. I guess I should get a new one but they cost huge amounts and I'm only really interested in spending loads if it has a touch screen and wifi (I think I'll be waiting a while).
tl;dr
How do I reboot my iPod so that I don't have to wait for the battery to run down to listen to it again. I'm at work and I need music to block out all the inane chatter.