I would imagine that anyone who is bothering to read this blog has very little difficulty with wasting time, but just in case you'd like to be a bit more virtually destructive while doing so, you might want to check out NUKEMAP. It's a Choose-Your-Own-Nuclear-Holocaust program that lets you feed your mass-murderous urges in a scientifically informative way.
The site is run by historian of science Alex Wellerstein of the Stevens Institute of Technology, who also writes the blog Restricted Data on topics related to nuclear secrecy. While it isn't the only app of this type to be found on the web, it's the one that I've had the most fun with.
And really, it's more fun than it probably should be.
Oh my, was that Gillette Stadium at the center of the blast shown above? Just a coincidence that this Falcons fan ended up there, I'm sure...