Apple was on hand in downtown San Francisco today to launch the iTunes Wi-Fi Music Store in Starbucks locations across the nation. This is the third major city to launch the service, with New York and Seattle launching back in October. Los Angeles and Chicago are due up in February and March of 2008, with many cities to follow after. For more info, check out our coverage of the New York launch. [Starbucks-iTunes Alliance on Giz]