Will, thanks for the link. I'm 5'8" 202 lbs, and starting to look like I lift. Hopefully I add the 0.5 lb/in in the next two years so I'll be a big dork, instead of a just a dork.
Speaking of dorkiness, GrimmThing, nice job! I checked your math (cause I'm a dork), and I get the same answer. I assume we did the same things. Say the density is a constant, use a cylinder for the volume, and say the radius/height is a constant. Get mass proportional to h^3.