I recently purchased myself an iPod mini, not because I'm an apple fanboy (in fact I loath OSX but thats another topic) but because it was cheap (relatively), has a good battery time and decent storage for its size and price. Combined with the fact that I can ditch the apple firmware by using Rockbox and I was sold
Anyways, while waiting for it to arrive, I decided to read up as much as I could on installation
before I start mussing with it, only to run into a dead-end in figuring out what version I was getting. Normally everymac.com would be my first stop but I've had issues getting there for some time and google wasn't much help either until I stumbled upon
this. Its apples own doc on how to determine which version of the mini you have and given how simple the differences are (clickwheel coloring, laser etching et al) I would have thought they'd be already in the documentation; instead is simply red text reading "Describe how to identify 1/2G"
I'm not faulting the devs on this or anything, its just surprising given how seemingly important it is for you to know what version you have, that the info needed for others to figure it out isn't more readily available, hence this post. Hell, for all I know the person writing the docs doesn't even know how to tell, which would explain why that bit hasn't been filled in

Anyways, beyond the above mini-specific page,
this page helps you determine what Gen you have of just about all the other iPods on the market.