Determining 3G vs Edge

Using private APIs, you can read this information directly in the status bar.

https://github.com/nst/MobileSignal/blob/master/Classes/UIApplication+MS.m

+ (NSNumber *)dataNetworkTypeFromStatusBar {

    UIApplication *app = [UIApplication sharedApplication];

    UIStatusBar *statusBar = [app valueForKey:@"statusBar"];

    UIStatusBarForegroundView *foregroundView = [statusBar valueForKey:@"foregroundView"];

    NSArray *subviews = [foregroundView subviews];

    UIStatusBarDataNetworkItemView *dataNetworkItemView = nil;

    for (id subview in subviews) {
        if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
            dataNetworkItemView = subview;
            break;
        }
    }

    return [dataNetworkItemView valueForKey:@"dataNetworkType"];
}