Do any of you use these? If so, are there any particular exercises you recommend with these? Oh, and what weight?

There's all sorts of cool stuff you can do! I do a lot of core work with 6lb-ers. I pull my knees up towards my chest and balance on my butt and twist from side to side, dropping the ball and picking it up on each rotation. I LOVE doing stuff on the bosu ball with medicine balls, too. With a 4lb one I will balance like I do in the previous one except on the soft part of the bosu. I will have a partner toss it down to me and I heave it back up.

I also stand on the hard part of the bosu and heave it against the wall, 3 sets of 20. Such a great total body work out.

I will stand on the ground, legs shoulder width and do a squat. When I come back up I heave it against the wall and go into a squat mid catch. Repeat 3 sets of 20.

I realize the descriptions aren't great, so I will try to find a website that does a better job. I really love them and think they are great for the whole body, not just arms!

I dont know what weight it is, but i sometimes hold a medicine ball when doing sit ups, and you can do walking lunges with them- basically do a lunge holding the ball out in front of you, and once you are down into the lunge, twist to one side and back with the ball held out in front of you, change legs, repeat twisting to the other side

I do side lunges with a medicine ball, not sure about the weight of the ball. http://exercise.about.com/library/blsidelunge.htm

Sweet, thanks for your replies! [Anyone else who has anything to add, please feel free]

Someone mentioned looking at TJ Maxx or Marshalls so I think I may do that today...if not I'll run by Target or Dick's.

Definitely check out TJ Maxx....I have seen them there before. I have also seen some at Target.

I like to use a 12lb. medicine ball for an arm exercise where you start with the ball in you hands, arms straight towards the ground, do a bicep curl, push the ball to the ceiling (working shoulders) and then back in a triceps dip and reverse. I usually keep doing it until my arms get fatigued.