Well, if you believe
the Discovery Channel, the earth
is building up for something spectacular -- the eruption of Yellowstone or one of the other calderas around the world (which erupt every 150,000 years or so -- guess how long it's been?).
Of course, if you follow the
link to the U.S.G.S., you can see that the probability is actually exceedingly small. Still, I'm glad to have a prairie and a mountain range between me and Yellowstone.

We have survived far worse than a super volcano before (quite obviously) and we'll do it again.
Another gamma ray burst would do us a nice number though.