Hmm, anyone from the UK remember those machines that measured shoe sizes? Its mechanical, but a few strategically placed motor operated 'levers' (poking in very personal places) could be used, either with simple motors and encoders or stepper motors. I'll be big, but I reckon it would work, plus, a PIC could do that with ease.
As for using light.....a PIC could do the scanning of a laser, and use a CMOS camera to pick up the reflection...but a PC would have to be used to get the information, and calculate area (and therefore chest size...waist etc..). The person in question would have to be in their birthday suit as well
Ultra-sonic distance measuring probably wouldn't be that accurate, and clothes would hinder propagation.
Either way, its a LOT of work. Theres a few random idea's....and after reading it back, the idea of a small robot getting 'jiggy' with a tape measure sounds more feasable. Still, dunno why people have to post pointless replies.
Blueteeth