I would be world leader in a couple of days.

Kill every major world leader. Proclaim that anyone who opposes me will die. Take control as the earth king.

damn, beat me to it!

I would go after the creators of Death Note for taking an interesting concept and making such a terrible (even for anime standards) show out of it.

But in all seriousness, I don't see all that much use for it. I don't have enemies in my personal life. Also, as a libertarian (non-initiation of force ect ect), I don't think it would fit well with my political ideals and ethics to use it ... unless it was on someone directly attacking me.

I'm sure liberals and conservatives would both have no problem doing away with "the other side" though.

Before giving me the book, may I please have your full name and a picture of you?

I probably wouldn't use a NOT DEATH NOTE. If I'm convinced that murder is the best solution to a situation, I feel like I should take responsibility for that murder, too. 

It's actually remarkably hard to instigate change via death. Take a political a revolution, for example. Most of the names you actually need to kill are not politicians, but the political donors. Politicians have a chain of succession. Political donors do not.

Just think about the can of worms killing a donor opens: before you kill them, you need to know all sorts of things like who their heirs are (and in what proportions), who those heirs would likely donate to, and what kind of estate taxes they'd face. This is comlicated by the fact that most rich people don't publicize their wills, and have charities as major recipients. Another major subset of political donors are businesses, and again you face chain of command problems.

Put bluntly, using this thing effectively requires an absurd amount of research. Some of the necessary information will be almost impossible to get legally and the very fact you are researching it will probably reveal your hand eventually.

I would start killing enemies of the environment, sport hunters, and anyone who is cruel to animals. Rapists would get it. Those who are consumed by greed, and those who exploit people would also get it.

hey! the first half is great, the second half though, can't say the same for that...

I would take over the world and build an utopian Canada ( which means I only need to had more strip clubs here and there)

I though I would have a MewTwo D:

Anyhow: "Many that live deserve death, and some that die deserve life." I would go from my home (the Shire), and eventually end up throwing it into the flames of mount doom. No biggie.