A friend of mine started wearing a weight strapped around his ankle every day. Over the past few months his legs have gotten quite a bit bigger and he can jump much higher. He never goes to the gym, so I don't know if he can life more, but he can dunk now and couldn't come close before he started wearing the weights. I wouldn't have thought that this would get good results because he isn't allowing the muscle to rest, and also because the amount of weight is rather low (I think 5-10 lbs per leg). However, it has worked for him, he's gained quite a bit of mass on his legs.
I guess I just want to know if this is a good idea for building mass or if his body is just responding to it differently than most people's would. If it works, it seems like a great way to get a work out while I'm at the office every day.