Q: He extraviado mi iPod 2G, ¿como puedo averiguar mi número de serie en iTunes?

Google translate:

Is there any way to find the serial number of the iPod? In my iTunes account wasregistered my iPod, I understand that it should be possible to find out.

See:

iPod: How to find the serial number

Also if you go to iTunes>Preferences>Devices and hover the mouse pointer over the iPod backup the SN pop up in a box.