WoW, 6 Months old already! The first half of a babies first year seems to fly by at the speed of light. Well, so does the rest... trust me, I know :) My Babies are 9 and 12!
Anyways, I think it is absolutely amazing how much growth happens during the first 6 months of life. I certainly would hate to double my weight in only 6 months. That could be a serious problem for me! (and for you too!) But for a 6 month old, that's good. It's a sign of good health. It also means that the baby is doing a lot of eating and we all know who's watch thats on :)
At 6 months old I like to capture the new little personality of your child as they laugh and play and flirt. 6 month olds are curious and like to move.