Lets say 10 people have an iphone with the same app on it.(they work at the same place)
Is it possible to find the nearest person to me, so i can message him then?
the problem: it must work accurate and also within a 5-story building.....
Can this be done?
Thanks goup!

I highly doubt that this is possible within current corona framework, or for that matter any other usual SDKs for iOS dev.

You will definitely need some external hardware to achieve what you want.

I don't think you can track height, as in which floor you're in inside a building.

Your app could post coordinates to your web-server, and poll the server for locations.

http://developer.anscamobile.com/content/location-gps
http://developer.anscamobile.com/content/gps
http://developer.anscamobile.com/partner/mapview

Yeah that's probably the way to go, but I don't know if that'll work indoors or be accurate enough for the use case you describe.

With the iOS SDK you could probably do something involving short range Bluetooth communications, but I've never seen anything like that in Corona.

thanksall for the answers. what i thought so yes.
bluetooth will only work extremely nearby, so thats not anoption
in a large building im afraid. extremeley good gps reception will
give more accuracy....but thats just the case:its in a bluiding....
phew :0)
thanks all

very crude and highly technical hack would be to use wifi signals from different routers/access points and use triangulation to determine user coordinates. dunno if it's even possible.. But meh.. someone had to suggest it :D