I have two thoughts. One, this is really cool. And two, I wonder what Hipmunk thinks of this?
Bear with me: imagine you could see where your friends have traveled on this map. You enter a budget range much like you do and it shows you the options. Then, you could see any pictures your friends took on such trips. And with a FB message/email, you can ask them how much they spent, where they stayed, what places they loved, how the food was, etc.
Okay, who has built this?