Hi Geoffrey Here's a simple category on NSDictionary for making JSON requests and converting data.

gistfile1.m

#import <Foundation/Foundation.h>

@interface NSDictionary (JSONCategory)
+ (NSDictionary*)dictionaryWithContentsOfJSONURLString: (NSString*)url;
- (NSData*)toJSON;
- (void)pushToURLString: (NSString *)urlString method:(NSString *)method delegate: (id)delegate;
@end


#import "NSDictionary+JSONCategory.h"

@implementation NSDictionary (JSONCategory)

+(NSDictionary*)dictionaryWithContentsOfJSONURLString: (NSString*)url {
    
    NSData* data = [ NSData dataWithContentsOfURL:
                    [NSURL URLWithString: url] ];
    __autoreleasing NSError* error = nil;
    
    if (data == nil) return nil;
    
    id result = [NSJSONSerialization JSONObjectWithData:data
                                                options:kNilOptions
                                                  error:&error];
    if (error != nil) return nil;
    return result;
    
}

-(NSData*)toJSON {
    
    NSError* error = nil;
    id result = [NSJSONSerialization dataWithJSONObject:self
                                                options:kNilOptions
                                                  error:&error];
    if (error != nil) return nil;
    return result;
    
}

- (void)pushToURLString: (NSString *)urlString method:(NSString *)method delegate: (id)delegate {
    
    //convert object to data
    NSData *jsonData = [self toJSON];
    
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL: [NSURL URLWithString: urlString]];
    [request setHTTPMethod:method];
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
    [request setHTTPBody:jsonData];
    
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:delegate];
    [connection start];
    
}

@end

// Sample of how it is used to make a get request.
// This is from a game I am working on, so it is passing the lat lon coordinates and returning a list of objects
// that will be placed on the map.
NSString *url = [NSString stringWithFormat:@"%@/%@&radius=%d", kBaseURLString, [self appendLocationToPath:@"items.json"], radius];
dispatch_async(kBgQueue, ^{
    NSDictionary *data = [NSDictionary dictionaryWithContentsOfJSONURLString:url];
    [self performSelectorOnMainThread:@selector(loadItems:)
                           withObject:data waitUntilDone:YES];

});

// A sample of posting data back to the server.
// This passes the user data, and a list of items that the user has collected to the server.
NSDictionary *data = @{
                       @"items" : collectedItems,
                       @"user" :currentUser.toDictionary
                       };

NSString *url = [ NSString stringWithFormat:@"%@/items/collect.json", kBaseURLString ];
[ data pushToURLString: url method:@"PUT" delegate: self ];

// In this case I handle the response in the 
// "connection:(NSURLConnection *)connection didReceiveData:(NSData *)data" delegate method
// because there are multiple requests with very near identical responses so it was
// easier to handle them all at once.

// Always interested in feedback if you have any ideas.

// Best

// Tim