Frommer versus Siri
Google's move this week to purchase Frommer clearly seems to be part of a larger effort to build up their Knowledge Graph, which in turn is designed to answer search queries directly rather than just providing relevant links. If users now query 'famous jazz composers' they are presented with an image ribbon of jazz legends, selecting one will take the user to page with a short bio and other data. It is similar to what happens when an iPhone user asks Siri who Miles Davis or John Coltraine is.
Google has to borrow content from Wikipedia and others to describe the jazz legends, the Frommer content will allow Google to answer travel queries with reduced reliance on third party content. ReadWriteWeb describes Google's efforts as attempting to become the 'Star Trek computer', which seems to be a popular goal nowadays. The blog Technically Personal outlined a growing number of Siri competitors and ZDNet published a Piper Jaffray score sheet breaking out the specific strengths of Siri against the various Google efforts. Siri will always have an iPhone advantage since she can work freely with scheduling and other native apps. Google appears to be extending its lead in search and will have free reign to present the facts in Android systems.