A lot of you probably know this, but I know some people might find this helpful. As we all know, normal capos are a tight fit on sevens. I've had the same Kyser for ages, and picked up a new one yesterday - this guy here, which is a 12 string capo:
Buy Kyser Quick-Change Capo 12 -String | Capos | Musician's Friend
It's a bit wider, and it is awesome. It fits on the 12 perfectly, and the extra coverage makes it a bit easier to throw on a six string, and works great on a seven as well.
Here are a few pics of them both - the decidedly older looking one is the standard capo, the longer, new one is the 12 string.
On my acoustic:
On my 12 string:
And both on the seven string 2027.
I'm going to buy a couple more of these right now. Not only do they fit wider fretboards, but the extra playroom on standard width necks is great to have.