I've been trying to take pictures every two weeks since I was sixteen weeks just so that I could see the difference. It wasn't much at first, but I think our little munchkin is growing by leaps and bounds now!
The funny thing to me is that everytime I'm going to take each week's picture I think, "Boy! I'm really big now!" Then after I see the picture I'm amazed that I don't look quite as big as I think I do. :)