// ...

- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken
{
    NSString * token = [[[[deviceToken description]
                        stringByReplacingOccurrencesOfString: @"<" withString: @""]
                        stringByReplacingOccurrencesOfString: @">" withString: @""]
                        stringByReplacingOccurrencesOfString: @" " withString: @""];
    // ...
}

// ...