I have done it! I have created the JoeUser Frappr. (Hopefully there wasn't already one...I did a search and didn't see it.) In any event, you can add yourself by following the link below.

Information about Frappr (plagiarized from their website):

Frappr was created by Brian, Kun and James at Rising Concepts, who wanted to see where all their
high school and college friends went after they graduated.

Frappr (Friend Mapper) lets you see the zip code where your friends live or work, letting you find out
who works in the office building next door and who lives in the apartment complex across the street.

Have fun!

I admit that I try not to join every single thing that rears it's ugly head on the net - before too long you are overrun with passwords and usernames and can't keep them all straight! But this one does seem pretty neat, and as an employee of Stardock I thought I should take it upon myself to start the JoeUser Frappr.

Hope you have fun!