Yes, it's true- you can now order iPhone 5S online through Apple’s website or one of Apple’s partner carrier websites including AT&T, Sprint, and Verizon in the U.S.!
Those who want to avoid buying online, can pick one up at an Apple retail store or carrier store later today, but here's a warning - the same supply constraints apply in those situations. And the huge lines are still a problem as well, so if you're not in line, you may not be able to get the phone for now. Oh, and consider that some stores are said to have received little-to-no stock of certain models.
Check the images provided below, describing the long lines formed at Apple Stores around the globe for iPhone 5S retail launch!