1 is probably the most literal and informative, but something about the guys head bothers me...it's so msft little people, and it feels dull.

I like #4 the most because it feels a little more fun and fresh, even though it's not literal. The motion of the lines give it a little spark that #1 lacks. If there will be text next to it explaining what's going on, then #4 is the best. If it's stand alone, then maybe rework #1 to have a little more motion/energy in it.