iPod iPod stolen, but was not last iPod plugged in...

I'm pretty sure my iPod was stolen (I can't find it anywhere, and I'm almost positive I left it at school) and I want the serial number so I can call Apple and register it as stolen.
The thing is, it was not the last iPod used on my computer- I had my old iPod that wanted to use to have some music to listen to.
I know how to get the serial number of that, but how do I search further back?

Thanks!

I still have the box, yes

eluk said:

You'll find the numbers for all iPods connected in ~/library/preferences/com.apple.ipod.plist

Click to expand...

What is that? I have a PC, sorry. D:

OllyW said:

The serial number is printed on the bar code label on the box.

Click to expand...

Haha, thanks. I just found that it says SERIAL NUMBER right on it.

Thanks again!