Colby is getting much better at sitting up. I think his big tummy gives him an advantage in this department (although it's a hinderance when attempting to roll over). Tummy time can last for all of 3 minutes now without him pitching a fit. He can lift his whole chest off of the ground. I am sure that one day I'll look down and he isn't where I left him - YIKES! For now I am still loving his immobility.