1. My housemate John reports that it’s possible to kill a fly in mid-flight by shooting it with a rubber band. I have yet to test this, but it sounds quite diverting. I imagine a squirt gun is also quite effective.
10. Get a cup of orange juice with a foil lid (or any cup that can be sealed). Open it halfway and wait for a fly to crawl in. Close the lid. Shake. Open it up and wait for another.
11. Exhaustion. If you make the fly stay in the air for a long time (15 to 20 minutes), it will be so tired that you can squish it with minimal resistance. My advice is to try to keep it pinned on one side of the room.
100. Use a flyswatter. It’s interesting to note that when you carry around a flyswatter, people ask you strange questions like “why do you have a flyswatter?”