I remember reading years ago that fidgeting can potentially burn up to a couple hundred calories a day. Don't know if that's really true or not, but I was always a fidgeter and since reading it I've often made a conscious effort to keep some part of my body in motion most of the time. My husband teases me about my "happy feet," because I'm always tapping them or bobbing them or waving them from side to side in patterns (I mean, as they dangle or as I sit with my legs stretched out in front of me, not like, waving them around in the air). I tap my fingers, I bob my knees, I rock or bounce when I'm standing somewhere.  I can't imagine just sitting still, like a lump, for longer than ten minutes or so.