I found what looks like a pretty good fan that can be clipped to all kinds of objects for expediency. Internal li-ion battery can be recharged by USB while itís running if your USB can push 2 amps. Iíve got a number of USB sources from wall plugs to power banks to that Goal Zero Yeti 400, afaik only the wall plugs push 2A.

While I was looking at USB fans I also found the AC Infinity USB Fan which Iím thinking might be useful for fabricating a USB powered swamp cooler. Just a thought.