First, find out what rules I'm playing under. Not much point to being the ruler for the day if I'm bound by the rules of, say, the President of the United States, who has the actual power to do just about bugger all. Second, find out of my rulings stand after the day ends. If everyone will just switch things back tomorrow, not much point in not spending the day faffing about.
If I really do have absolute power, and my decisions stand when that day is over, then I obviously have far more options.
1. Legalize gay marriage worldwide.
2. Revoke tax exempt status from any church that argues against 1. The law won't force you to marry people, and if they really are of your religion they won't want to violate your rules. But your rules don't apply to anyone who isn't your religion, so suck an elf and get over it.
3. Legalize soft recreational drugs (like marijuana), but vastly increase the sentences for public intoxication. Set up safe houses for people who want to get high, and have them paid for by drug sales. Driving a car under the influence of anything, even alcohol, is considered attempted murder. I don't care what you do to your bodies, but you endanger other people with your stupidity and you go down hard.
4. Bomb the shit out of the Westboro Baptist Church. Because fuck those guys. If I had longer than a day, I'd enact a law that forces them to sit down and shut up, but at the same time has enough provisions in it to not turn into a tool for the government to potentially shut down people who aren't massive tools. But I only have a day, so the hell with it. Bombs away, you guys asked for that.
5. Demand Namco-BANDAI translate and release IDOLM@STER outside of Japan. I want to play that game.
6. Outlaw war entirely. All international disputes will be settled on the football pitch. Best team wins.
7. Demand American football change its' name. That is not a football. And as you all have to do what I say, you will get with the rest of the world on this.
8. While we're getting you caught up with the rest of the world. Celsius. Metric. Learn it.
9. Find me the Fox executive who decided to cancel Firefly. We're going to shoot him on live TV. Not kill him, just like shoot him in the leg or something.
10. This [http://www.youtube.com/watch?v=VGOMnE26jNo] is a French cartoon that was translated to English and run when I was little. Figure out who has the rights and put it on DVD.
11. All secondary schools will teach a class on actually living as an adult when you get out of school. Budgeting, cooking for yourself, an understanding of how your government works, critical thinking, spotting bias in news stories, et cetera. The class is vital to graduation, and rather than a final exam you can cram for, you will be expected to prove you have really learned the material over the last couple of months of school.
12. Science classes will become far more emphasised, and also a requirement for graduation. Evolution will be introduced as early as possible, and a full semester of secondary school will be spent on the scientific definition of "theory". Another semester will be spent on dinosaurs, because they are awesome.
13. Demand that serious effort be put into making petroleum-free cars. Any automaker who has not started production on a hybrid by one year from the date I take power will lose their license to operate in every country. They have five years to get a petrol-free car working. Get started.
14. Moon base. Get planning.
15. Reality TV is banned. The History Channel will be about history again. Anyone wishing to put forward that aliens, ghosts, bigfoot, demons, or any other sort of cryptozoology actually exist will speak to the scientific community, not put a television show on Sci-Fi.
16. Educate all of humanity about their right to not be offended. This right is exercised by walking away. Don't like seeing something? Stop looking at it. Don't like what someone is saying? Stop listening. Massive jerks will get what is coming to them (see #4), but, as an example, if seeing a woman breastfeed her child in public, or a gay couple kissing bothers you, stop looking. Problem solved.
17. Airlines will measure passengers by girth. If you exceed the size that one seat will hold, you will buy a second seat.
18. Demand a meeting between various Middle East and Western leaders. They will be assigned to Jury Duty hell. They will live in hotel rooms, spending 100% of their time at a conference, and unable to leave until they work out their differences. The Israel/Palestine thing will be sorted out, as well as the general theme of anti-Westernism. A workable solution FOR ALL PARTIES will be found, or they're not leaving.
19. Sting vs. Undertaker. WrestleMania. Make it happen.
20. Tigers are the official animal of the entire Earth. Breed them, take care of them, get them off the endangered species list.