How do I reboot my iPod?

With the hold switch off (i.e. no orange showing) hold down the menu and center buttons for 6 seconds.

That should work on the fly, as for a true restore, that's done from your computer.

If you are talking about a "reset", follow Deggie'instructions. If you need to restore which will put the Nano back to factory settings including removing all your library, that has to be done on your computer.

actually, sometimes it does not respond to the computer, and, ****, you must hold down center and menu buttons for 6 seconds! (toggle hold switch if you want to)