Google: Suspended Leg Curl
or just see this video:
http://www.exrx.net/WeightExercises/...STLegCurl.html
Great exercise, you can make your own suspension trainer for cheap:
http://rosstraining.com/blog/2010/01...nsion-trainer/
Then your exercise options will be wide open.
Also, if you purchase some resistance bands you can do these:
http://wn.com/Band_Leg_Curls
Some other good options that don't require equipment:
Bodyweight lunges and split squats.
Also standing broad jumps.