End of The World Science

I've been having nightmares about the end of the world a fair bit these days. Thankfully someone has provided a guide to the top 10 ways to destroy the earth. I'm sure there are some more exciting options that could have made the top ten. Anyway, my favourite from their list is #2: "Eaten by von Neumann machines". Awesome. Anyway, there is a fair bit science talk on that site so it might not make a whole lot sense but anyway... I've always wondered what would happen if we stopped the moon from revolving around the Earth? Would it just drift into Earth in one almighty collision? That would be awesome. I want to try that one day and see what happens. This site has more end of the world scenarios, although I haven't looked very deeply into it yet.