Although these bots have a long way to go before they're able to beat a human team of soccer players, the RoboCup organizers say their goal is to have a team of fully autonomous humanoid robots that can beat the world champion soccer team by 2050, so they have plenty of time to practice. Meanwhile, the annual world championship, RoboCup 2007, is underway in Atlanta, and here's some action from the preliminary game between the Darmstadt Dribblers and CIT/H.
The robots compete in a variety of categories, with the small ones (that look more like hockey pucks than bots) limited to a size of 180mm in diameter and no higher than 15cm, and there's also a medium-sized league, and a four-legged league of Aibo-style bots that operate fully autonomously with no human interaction or external control. They are arranged in teams of four, playing on a 6m x 4m field.
These humanoid bots are divided into two classes, kid size (30-60cm in height) and teen size 80-130cm), and they have human-like senses and can run after the ball, kick it, and make their own decisions. So far, they look pretty lame, and remind us of small children just learning how to play soccer with their parents setting up all the shots. But if you consider what they're actually doing, it's downright remarkable. Check out the little goalie making a save.
RoboCup World Championship [RoboCup 2007 Atlanta]