Team Maker is a simple Web page that takes a group of names and randomly groups them into any number of teams that you specify. You'll just want to have a complete list of names handy to paste into the Web page's name window, which starts out thoughtfully populated with characters from The Office.
The page also names your teams for you -- choose from among a handful of team naming themes, such as dinosaurs, birds of prey, cars, and sports teams. You can rename the teams to taste or, of course, ignore the team names completely.
This little one trick pony is a cool little site to bookmark and save for some corporate event that calls for random teams (and which no one remembered to create ahead of time). Whip this out, print the resulting team names, and you'll be the hero of the morale event.