According to Venture Wire (via VentureBeat) "virtual personal assistant" Siri has raised $15.5 million in a second funding round. The first round was $8.5 million. Built on artificial intelligence coming out of SRI, Siri uses voice input to enable a more "transactional" user experience on mobile handsets. It taps into various APIs to accomplish tasks, such as making dinner reservations, calling a cab or adding dates to one's calendar. 

In this respect it goes beyond basic search and information retrieval into the realm of "transactions." A significant US carrier deal is coming, as well as an iPhone app (hopefully very soon). 

Without having used it but having talked to spoken numerous times CEO Dag Kittlaus I can say it's one of the most interesting startups in the mobile ecosystem.

Here's a recent post I did on Siri at Search Engine Land: Does Marissa Mayer’s “Perfect Search Engine” Already Exist In Siri?