AFOAuth1Client *twitterClient = [[[AFOAuth1Client alloc] initWithBaseURL:[NSURL URLWithString:@"https://twitter.com/oauth/"] key:@"..." secret:@"..."] autorelease];
    
// Your application will be sent to the background until the user authenticates, and then the app will be brought back using the callback URL
[twitterClient authorizeUsingOAuthWithRequestTokenPath:@"/request_token" userAuthorizationPath:@"/authorize" callbackURL:[NSURL URLWithString:@"x-com-YOUR-APP-SCHEME://success"] accessTokenPath:@"/access_token" success:^(AFOAuth1Token *accessToken) {
    NSLog(@"Success: %@", accessToken);
} failure:^(NSError *error) {
    NSLog(@"Error: %@", error);
}];

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
    NSNotification *notification = [NSNotification notificationWithName:kAFApplicationLaunchedWithURLNotification object:nil userInfo:@{kAFApplicationLaunchOptionsURLKey: url}];
    [[NSNotificationCenter defaultCenter] postNotification:notification];

    return YES;
}