Well, that didn’t take long. The NPD Group reports that Google’s Android OS outnumbered all other smartphone operating systems on devices sold in the US during the second quarter of this year. Android captured 33% of smartphone sales in the quarter, moving ahead of RIM, whose share dropped to 28%. Despite a “small gain” from the iPhone 4 launch at the end of the quarter, Apple only managed third place with 22% of the pie.

Of course, there are quite a few more Android-powered devices than there are handsets running iOS. Among Android smartphones, Motorola’s Droid proved to be the most popular. Behind it, four HTC models rounded out the top five. Keep in mind that these figures only apply to U.S. sales, though.