The act has to be small(ish). You can’t say “Make everyone vote a certain way!” As an example I’ll give mine.

1. Take all of the money I currently have in savings and invest in Nikola Tesla and attempt to slander Edison.
2. Ride the train with Edgar Allen Poe and make sure that he made it to wherever he was going safely and keep an eye on him for a few days to make sure he was ok.
3. Sit on top of the library of Alexandria with a SOPMOD and several hundred magazines worth of ammo.

Update: gotta say, there’s a lot less “save my favorite musician from death” or some such than I thought there’d be.