Our sweet baby gained 2 1/2 pounds in the first month of his life. His belly is huge and his fingers, toes, and cheeks are pudged out. :) He weighs a whopping 8 1/2 pounds these days, and he's doing all sorts of amazing things like looking at us, grabbing our fingers, and fending off his hungry father. :)
Don't be alarmed by the oxygen tank--we live at over 10,000 feet and almost all babies here are on oxygen for a couple of months. It's very annoying to drag that tank around, but it could be worse. :)