This one is my favorite. I need a fan when I sleep. But they take up room in my suitcase. I found a solution using a PC fan.

This isn't the cheapest solution, but I figure the weight savings is worth it. I found a PC fan (made by Silvertone) which has a super high air volume output. It is not like a box fan, but enough that you can feel it several feet away. They run off of 12v DC, so I also bout a AC/DC converter with the appropriate connectors. Also, I found a neat speed control that you can plug in to adjust the fan speed. It's nice because you aren't just limited to one or two speeds - it is continuously variable. To hold it up I bought a picture stand at the craft store. It props the fan up so it doesn't fall over.

The one challenge was finding a back grill. They come with only the front grill, and the back grill was hard to find. One of these days I am going to laser cut or 3d print one, as the one I have restricts airflow a little too much.