The good news (or possibly bad news, depending on your point of view):
destroying the Earth is a lot harder than you'd think. Nuclear weapons, armageddon, gay marriage and proving that 1=0 will all fail to do anything about the planet still being there and all in one piece. Of course, if you'll settle for merely wiping out much of life on Earth, that's somewhat easier. (via Bruce Schneier)
I found this page a while back and on the page that it was linked from, I found this:
<blockquote>Trust Us: "The most likely way for the world to be destroyed, most experts agree, is by accident. That's where we come in. We're computer professionals. We cause accidents."</blockquote>