http://www.boingboing.net/2010/10/06/nimblestrong-the-iph.html
My daughter's first video game obsession? Nimblestrong, an iPhone game that teaches you how to bartend as you select, drag, and time your pours of various drink recipes into appropriate glasses - complete with garnish. All the while, you are encountering strange and exotic patrons as you train to become a hero master bartender.
It's actually one of the better examples of a video game being used to teach a specific skill that I've come across, with a good balance between twitch, recall, and narrative. There's just something deeply compelling - and rewarding - about successfully completing a complex drink and getting high scores from that anime vixen who thought you would screw it up.
The best part is the sound effects, and the particularly retro vidgame score. That, and the fact that my five-year-old now knows how to make 57 drinks.