How can I get rid of pubic lice?

1) I have recently discovered that I have what appear to be crabs in my pubic hair. They are itchy and annoying and appear to be laying eggs. How do I get rid of them?

2) I think I have pubic lice, a.k.a. "crabs." Do I need to see a doctor about this problem, or is there over-the-counter medication of some kind I can use to expel the little buggers from their new home? Also, I'm curious as to how I got them since I haven't had sex for several months and this is a recent development. Can one contract this problem from sharing clothing, towels, or bedclothes?