Ryan is 4 months today and rolled over last Sunday, he pushes his head up really strong when he's on his tummy, dribbles a lot (he's teething), makes a lot of screaming happy noises, can mimic us, laughs, cries real tears, can hold/grip things with his hands (can take his dummy out and hold it, can shake hand held bells/maraca).
Think that's it really, he's very strong though he always has been.