I tried Hipmunk for the first time last week. I really enjoyed searching flights by "agony". Unfortunately I learned the hard way that all Delta flights should be put at the very end of the list when sorted in such a way.
Actually google does hotel pricing already in maps. It's not super obvious, but do a search for "hotels in San francisco" and you should see some prices
Or, another failed startup. This is the scary road you tread when you're in a space that might raise the eyebrows of a company like Google. High risk, high reward. I wish them luck!
It'd be cool if they could handle other itinerary and reservation tasks. Though I don't know how they'd necessarily make money like that.