An interesting project from Microsoft Office Labs: Ribbon Hero.
Ribbon Hero is a concept test for Word, PowerPoint, and Excel 2007 and 2010, designed to help you boost your Office skills and knowledge. Play games (aka "challenges"), score points, and compete with your friends while improving your productivity with Office.
It was developed in conjunction with Dan Cook, author of the Lost Garden blog (I've blogged about him before). Cook has a great post up about how game mechanics can help users learn systems that support "more complex interactions than typing a word in a plain vanilla search box."
If you start with the idea that users are learning machines, all our observations about usability tests snap into place. Of course, people stumble when they use an application for the first time. They don’t understand the interface because it is new to them. And users will stay at that inexperienced level if we do not make an attempt to teach them how to improve. We’ve diagnosed a burbling baby as a hopeless invalid, blind to the fact that babies grow, learn and flourish.
Worth reading in full. And if I were running Office on Windows I'd be playing the game.