Reverse time and become a God.

Tell Bill that it'd be a nice idea to go Open Source in the very first moment he starts making windows

I like this idea as well.

And yet, this is probably the most useful suggestion in this topic.

This makes me think about how horrible it would be to be aware of everything in the universe and all of the mistakes humans make. Sort of like watching someone learn starcraft and wanting to yell at them to just right click somewhere to move a unit instead of clicking the move button...

Hiroshima and nagasaki were mostly insignificant cities, militarily-speaking. It was later revealed that the US nuked them to test what would happen to large cities and amounts of people when nuked. The story that it was the nukes that scared the japanese into submission was just a useful cover. And no I'm not a conspiracy theorist, I forget where the video is but they actually confessed to this. They were rather embarassed about it IIRC.

If it's true, I should say so. Killing tens of thousands of people just to see what would happen is horrific.

Duke Nukem Forever. 'Nuff said.

Prevent /b/ from existing.

Prevent Farty from existing.

Wait I think I saw this in a movie once...

1) Prevent Islam from overtaking the Arabic world. Arabic mathematics was so far ahead of anything the human race had seen it got to the point of ridiculousness. Computers would be much more advanced by now if mathematics hadn't be quashed out of the region.

2) Kill Thomas Edison. All technology, in all fields, would be 30-40 years ahead of its current place if Nikola Tesla had had a less dickish boss to deal with.

3) Convince James Sidis that it was all worthwhile. He could have done anything Tesla did, and more, and had he actually contributed actively to the fields of physics, the minds of modern scientists such as Stephen Hawking would have been able to learn from the things he did, and be much further ahead in their own works.

4) More evolutionary pressures on modern humans.