I think I posted this on the training board, but anyway--
If you don't want bigger legs, you might try a different approach to exercising them--find a ballet class, or try Pilates (the reformer, not the mat class.) Both will use Isometric prinicples to work the muscles, and will stretch your leg muscles out.
I used to do a lot of Pilates as a rehab exercise when I hurt my neck (insurance paid for lessons!) and I think it's a great alternative to weights/machines.