So it turned out that I didn't need to upgrade my entire operating system for it to recognise my new-to-me iPod Touch, just iTunes. (I gave up updating iTunes some time ago because each new version was more annoying than the last.)
I have synced music, photos and contacts from my Mac, I have set up my email and successfully connected to Catbasket, the house wireless network, and I have downloaded a bunch of pointless timewasting crap from the App Store.
Now I can Tweet about what I'm having for supper while I'm actually eating it, and send emails with a smug 'Sent from my [device]' signature. FEAR ME.
The one thing I haven't tried yet is listening to music on it...