Ok, so I'm not sure how old this practice is and why I've never heard of it, but I was looking up body modifications and I ran into some of this stuff. It's apparently pretty popular. A man can fill his sac with saline (Saline is most popular, although I have heard of other things being used...) and appear to have huge balls for days until the solution is gradually absorbed into the body. Best of all, it's safe and you can order legitimate supplies online. Here's a site with some pictures... although if you google scrotum inflation, scrotal infusion, et cetera, et cetera, you can find out more.
If any guys are interested in trying this (I'm a girl.) let me know, PLEASE! It's so hot. :D