Welcome to Chat Roulette. It's simple: The site pairs you with a random videochat partner. You can click "next" any time, or stay with your current pairing.
Then things start tripping into psychedelic performance-art territory. As a friend says, "It's the Internet. UNFILTERED." The big lure is basically seeing something strange—or doing something so strange that you blow your partner's mind.
You might see people in horrifying masks dancing around. Chinese users seem to love virtual high fives. One person's shtick is a puppet who makes like a caring psychotherapist and will sit with you for hours. A friend reports a man holding up a sign that said, "Assroll?"—and promptly rolling over backwards, naked. (Nudity is hard to avoid.)
Also, challenges are big—successively crazier things. You might start by eating a page of your favorite book. You might end by calling your mother and screaming that you're being murdered. Think of YouTube, with even more exhibitionism because everything is live and nothing is being recorded.
This appears to be the place where all the freaks trawling 4chan—a bulletin board better known for inventing LOL Cats and Rick Rolling—have migrated their insanity. And it's insanely addictive—basically like a slot machine where instead of cherries, you're hoping for the strangest that humanity has to offer.
Self-published entertainment has officially moved into territory I can barely comprehend. Parents: One more reason to lock up your daughters.