Just six months ago in May, Google announced during its I/O conference that it had activated 100 million Android devices. Today, in the midst of the big Google Music announcement, the company is doubling that number, claiming there are now 200 million activated Android devices. Yes, Android’s plot for world domination continues to move forward.

Just yesterday, a fresh batch of numbers from the Gartner oven revealed that Android is now responsible for 52.5 percent of worldwide smartphone sales as of Q3 2011. That’s a dramatic leap ahead of Nokia’s Symbian and Apple’s iOS, which captured 16.9 percent and 15 percent, respectively.

There is a bit of underwhelming news, though. Jamie Rosenberg, director of digital content for Android, announced that Google activates 550,000 new Android devices on a daily basis. That’s the same number from July. To Google’s credit, it’s a very big number that isn’t by any means shrinking, but it hasn’t increased either.

Perhaps the phone that has best contributed to Android’s growth is the Samsung Galaxy S II. The Galaxy S II has seen very impressive sales: Samsung announced last month 30 million Galaxy S and Galaxy S II combined units sold. It’s one of the few smartphones that has managed to take a noticeable amount of spotlight away from the Apple iPhone.