Twitter, just as much as Facebook, is widely said to be behind the uprisings across the Middle East. Newt Gingrich used Twitter to launch his presidential campaign. And then there is Sarah Palin, who tweets about the President every time he changes his underwear (“Red stripes! He’s obviously a communist!”). People are made famous just because of their Twitter-appeal.  So who’s the biggest Twitterati of them all?

As of late Saturday night, it was Lady Gaga. She’s hardly a world leader, and while people are constantly commenting on her fashion sense, you don’t see a lot of people buying the latest styles at Santana Row butcher shops.

Nevertheless, on Saturday night Lady G passed a Twitter landmark by getting her ten millionth follower. Twitter claims to have about 200 million accounts, which means that 5 percent of all Twitter users follow Lady Gaga. And the number is growing too.

For the record, Gaga also has 34 million fans on Facebook. With that site having 600 million registered users, Facebook still comes out ahead, at least slightly.

To celebrate the milestone event, Lady Gaga tweeted, “10MillionMonsters! I’m speechless, we did it! It’s an illness how I love you. Leaving London smiling.”

Leaving London and illness aside, Gaga may still have reason to be worried. In her quest to conquer Twitter, she may have a rival. Justin Bieber is soaring through the Twittersphere with 9.671 million followers, including over 600,000 new followers in the last month alone. Roughly, that’s the equivalent of all of Baltimore’s population signing up to follow Bieber in a single month.

Gaga has still managed to maintain her edge though, and Bieber’s voice may yet crack. The real winner though is Biz Stone and the other Twitter founders, who launched the site less than five years ago.  With an annual growth rate of 1,382 percent between February 2008 and February 2009, they really may be on to something.

Read More at Media Bistro.