It's called Middow and it basically takes two locations and finds the midpoint between them. You can then search for pretty much anything around the midpoint and meet people in the middle or whatnot.
I have already pushed out the first update which will save addresses you search for so you don't have to type the same ones over and over. That should be approved by the App Store either tomorrow or sometime soon after that.
Also, if you wanna be a sport and give me some free publicity, digg this story!
http://digg.com/apple/Middow_Meet_in_the _Middle
Any tips, suggestions, praise?