Just read a kick ass Pulitzer Prize winner - The Road by Cormac McArthy. The setting is the earth about 3 years after some apocolyptic event. Not sure if it is an asteroid hitting the earth, a nuclear war, or a major volcanic eruption, but the earth is covered in ash, and all of its vegetation has died off. About 95% of the human population has died off as well. The story centers around a man trying to travel south with his son. They encounter some shady folks along the way and basic survival is a struggle. The writing style is very basic and lacks most modern punctuation, but it is easy to read after a few pages. A movie adaptation starring Viggo Mortenson is due to be released soon. Anyways, it's a good book if you've got some time to kill.