I just bought an iPhone 5, and was planning on listing my (what I thought, was) 5th generation iPod touch I bought last year, but Glyde and Apple support both claim there are only 32GB and 64GB 5th generation iPod touches, where as, mine is only 8GB.
My girlfriend has the iPhone 4S, and my iPod's screen is bigger than hers, which leads me to believe it is an iPod touch 5th Gen, but I can't find any documentation on it existing in the wild. It also has no rear camera, only a front facing one.
The model number laser etched on the back is: A1421