ruby on rails - How to design a location data app integrated with own RoR web site for iPhone -

simple concept: map users current location specific points of interest around vicinity.

details: have my own map mash-up web site, provides service people search for contribute gps location data of toboggan hills.

now need build companion iphone app site.

my challenge: i'm kindly asking input api tools/design best suit task?

i'm aware of core location framework. ignorant of how best go getting list of location data points own rails web site. (i didn't code web site, outsourced)

i'll need explain rails team site changes. figure out myself iphone portion.

ideally, i'm imagining protocol ask server give me list of location points within gps radius iphone in.
possible? tax server much?

downloading entire world-wide list of hills , filtering on iphone ones 'in view' seems inefficient.

how other apps it?

thank you.

you going down correct path. in nutshell want to:

1. have iphone provide updated location when user moves more x meters
2. take new gps location , make request server. (preferrably ssl posted key info prevent open access)
3. the server searches pois within radius of location , returns json or xml of poi gps information
4. use information draw pois

the question have, if want store poi info on device or if want fresh every time.