Worst case scenario is that they make rear racks that mount to the QR through the axle:

http://www.oldmanmountain.com/Pages/...RearRacks.html

Also, if you have a road bike, some road bikes have a triangle by the dropout and I believe Campy sold a little adaptor that allows one to use that as a lower eyelet.

I have a custom rear rack/pannier on my Lemond (no eyelets) that uses this. Basically it's a small rubber grommet that will fit in the triangle and I have the lower arm mounted via a nut and bolt through this grommet in the rear. It does limit the weight as it wont be AS secure as the QR mount or an eyelet but works fine for the 5 years I've used it to commute to work.

Jay