I don't think you need to be too nervous at technical speaking engagements. In my experience, most people just show up to hear you say the name of the talk, and then they tune out and start using their laptop. So if you pace around the stage, they won't notice, 'cause they're off in some other world.

(You could say, "Well, that's because all your talks are so boring.". Maybe, but this happens at even the most interesting speaker's talks as well.)