I always find Leon Redbone great to listen to AND to watch. Not only does he sit down, but he wears dark glasses and has his hat brim pretty far down in front. Not exactly "reaching out to your audience" body language -- but it works for him!

As for me, one reason I usually stand (except in a group where everyone else is sitting) is that I spend all bloody day sitting -- on the phone, at the computer, driving, etc. Standing (and moving around while I play and sing) is a welcome break!

Genie