http://www.mybodycomp.com
Someone recommended it on MIT BBS and I think it might be useful for people here. Seems it "will ask you to measure some various sizes like neck, shoulder, waist,
butt, thigh, calf, ankle etc, and you age, weight information, then it'll
calculate you body fat composition for you.
You can do that periodically and compare your data to get your progress. "

Now you can judge your fitness progress no just based on weight but a more reasonable and fair number: you body fat composition!