Joe over at the Schlabotnik Report picked up a nice stash of the 1970 Topps Super football cards recently and blogged about them a couple of weeks back so I'll spare you a repeat of the details but these are really pretty neat items. I have always been aware of the baseball versions of these but the football ones were unknown to me until a few years back. I hadn't pursued them until I decided to collect the Baltimore Colts cards from their tenure in Baltimore.
I will not attempt to collect every single insert and oddball card or set out there. That's just silly (there is a Topps test issue Unitas tattoo that cost more than my car). But the affordable and interesting ones are going to be in my sights.
My copy of the Unitas is a bit rough but I wanted to buy cheap and that's what I did. It's still nice enough to add to my binder. As Joe pointed out the reverse side of the card is identical to the regular Topps 1970 backs except for the card number.