I am in the process of building a location-based iPhone app and I am unsure of my architecture. I plan on using Core Resource (http://coreresource.org/) along with Core Data to manage the objects on a remote server. I then plan on sending the current location of the client to the server and querying for results within that geo-location. I am unaware of any alternatives to Core Resource or this architecture. Any tutorials or comments to point me in the correct direction are appreciated.
I've only recently started with CoreData (which is awesome), and have never heard of Core Resources, but it looks pretty neat. Right now though I'm using MagicalRecord https://github.com/magicalpanda/MagicalRecord in a few of my projects. Also Cocoa Is My Girlfriend had some articles about Core Data not too long ago that I found useful http://www.cimgf.com/
Hope that helps.
I ended up using SimpleGeo's Storage API for this. Parse.com also has a solution for this problem.