Snares would normally be my choice for trying to hunt in a survival situation, along with trot lines for fishing. I think Susan said long ago that using them was the sure way to be found, because as soon as you did a fiish and game officer would show up. However, as mentioned about, it's probably not a great idea when you want to move.
Hacksaw's idea of a slingshot is good.
Two other things you might look at are:
http://www.geocities.com/blowgunhunter/http://www.wildwoodsurvival.com/survival/hunting/slings/sstoneagesling/http://slinging.org/I'd try my hand at these things before I ever considered packing a bag and relying on them to eat.
Also, be aware that there is such a thing as rabbit starvation.
See:
http://en.wikipedia.org/wiki/Rabbit_starvation