Brewster, Koding, The Mill and our own Float. Like buying a car and then noticing that car everywhere on the roads, I've been struck by the number of logos that feature these odd-shaped stripes. One of our users, Avneesh, also keenly pointed out the Mac Mountain Lion Notification Center looks like the Float logo backwards.
Perhaps The Mill get the credit for starting this all. Or maybe it's the word processors, and Microsoft were the true innovators when they designed the left & right align icon for Office.