Apps Architect thoughts on a loopt style of application

[jamescraft34]

Hello.
I was kicking around an idea of an application that would be able to discover when others running the same application were within a certain distance to it. I figure this would need to leverage some sort of database storing location coordinates that the application can ping and update every x minutes.
Does anybody have any thoughts or alternative ideas to do this? Would love to see what others think...
Thank you,
James

 

[usml]

bluetooth. the distance is probably much shorter than what you have in mind. with bt it's more annonymous and easier to accept by most people, I guess.