The social network scene became even more diversified a couple of weeks ago when Google launched their new Google+ service on an invite-only basis. Just three weeks later, digital marketing monitor comScore Inc. estimates that Google+ had more than 20 million unique visitors since it debuted on June 28.

Google has taken what they deem as the best qualities from multiple networking communities and rolled them into a single package. Aspects of blogging, Twitter, newsletters and e-mail are some of the key features found in Google+.

Some have criticized the program for being too difficult to learn, while others see the forward thinking layout as a breath of fresh air and an escape from the general Facebook population.

Google+ still has a long way to go in order to catch up with social networking giant Facebook, which has more than 750 million active users according to their own statistics. But if history tells us anything, Facebook isn't entirely safe at the top of the mountain. 

MySpace became the largest social networking website in 2006 and remained so until mid 2008 when it was dethroned by Facebook. The site's storied fall from grace is proof that trends can shift rapidly in the social networking realm.

Google+ still remains an invite-only program which would seemingly hinder growth, but it appears that the limited access is only helping to fuel the fire and attract new users.

Have you signed up for Google+ yet and if so, what are your thoughts on how it compares with Facebook and Twitter?