Elynor has taken to sleeping on her side/tummy. I lay her down on her back and she immediately curls her arms in, moves her hands to her mouth (usually putting her pointer & middle fingers in) and wriggles to the side. Sometimes there are tears involved, and others none. This has become her get comfy/settle into sleep time routine. It's also become my cue that she's ready for a nap. When she goes from happily playing to whiny and rolling onto her tummy, off to bed she goes. And yes, I guess it goes without saying that she is officially rolling from back to tummy. Scary... this means mobility isn't too far off, right?!