High speed drawing, - at 70 mph. I wasn't driving I hasten to add, but sat in the front passenger seat. It made for an interesting exercise.
In life-drawing classes, sometimes the students are asked to draw very quickly with the model changing poses every 30 seconds or so. It heightens observational powers.You have to quickly decide which is the important information you need to put on the paper. I call it "outrunning a camera" which you could do in the days of mechanical, non-automatic SLRs but now with digital you just point and shoot. It can make you lazy.
But drawing just for its own sake is stil fun I guess.
Well I enjoy doing it!