In my continuing series of wish list items I’ve got a new web app mashup that I want. And I want it now. (Giving credit where it’s due, I was talking with Tara Brown when this idea started to take shape but it’s seriously bad ass and someone needs to get on it.) Basically the idea is a mashup of a handful of services that know who your friends are, where you and they are, and can suggest deals for you guys to visit each other.

The quick example is something that would look at your friends on something like Facebook, and cross reference that with friends on Twitter as well as seeing which ones of those you regularly interact with. It would then look at Dopplr or Fire Eagle profiles for those people to see where they are and where they are going to be in relation to you, and then check something like farecast to find when cheap deals for flights one way or another would be coming up. It could then even pair up with expedia or something to actually allow you to purchase the tickets. Hell it could even cross reference Seat Guru to find the best seats on the flight!

Obviously some level of currentness is important here, meaning you don’t want to know flight costs to everyone you are connected to on Facebook, you certainly do for some. Having the ability to flag certain people would be cool, but even cooler would be if it watched what you were doing with those people online and made those assumptions on it’s own. For example, it would be cool to get a notice like this:

Hi Sean Bonner, We noticed that you are frequently replying to tweets by _____ and also have sent them public gifts on Facebook. We just noticed that there is a deal on flights from where you are in LA to where they are in _____, would you like to see some travel options?

Or like this:

Hi Sean Bonner, We saw that you are planning a trip to New York City the first week of April. Did you realize that your friend _____ who you play a lot of Scrabulous with is going to be in Washington DC the following week? Even better, did you know that there is a super sale from ____ going on right now that can get you from NYC to DC for under $50. Interested?

The thing is we are all aready putting that info out there. These sites know where we are, who our friends are, and who we are talking to most often. Why not do something useful with that info?