what are you going to do.....rob their house/cheat on your wife/gf, be a stalker...I could go on and on with this..lol
Just j/king.....i know what you are talking about also seen the commercial.
Edit: Iphone Friend Locator "Brightkite"<--- I did a search on Google and this is what it more less gave me.
http://vimeo.com/1984673