Speaking as someone who has been hit(but not kicked recently) in the junk, the best thing to do is to lie on your back and rotate your legs like you're pedaling a bike. Don't ask me, I don't know how, but it will help. I did this after the last couple of times I landed on my nuts laying out for the disc playing frisbee, and I was up and playing again in a couple of minutes. I have nothing to back this up of course, other than my own anecdotal evidence. I tried to find some evidence on the web, but to no avail. Apparently testicular injury first aid isn't a big topic in medicine these days. If there are any med school types out there, your input would be appreciated now. Curling up in a fetal position is a bad idea actaully, as that creates the possibility of squeezing between your legs some VERY tender testicles. Seriously though, the best way to deal with this problem is to avoid it at all costs. It hurts a lot, guys, so if it hasn't happened to you recently, keep it that way.