Anyone know of a rear rack that will work with panniers that can be described as quick-release? Specifically I'm looking for a rack that doesn't just attach to the seatpost, but also has the "legs" that attach to the rack holes in the frame near where the rear wheel attaches.

I always thought it would be nice to have those legs be hollow and just slip over a small posts that that you attach to each side of the frame near the wheel. Combine that with a quick-release clamp for the seatpost and you've got a sturdy rear rack that can be quickly put on or taken off. Haven't found anything like this, though.