i found this site after seeing the End Day program on National Geographic about natural disasters. i found it very entertaining and quite funny. it basically lists different ways of totally destroying earth. but thats the whole funny part, its not at all possible. anyway, its worth a look if you have appreciate a witty, dry sense of humor along with some interesting science.
http://ned.ucam.org/~sdh31/misc/destroy.html
http://ned.ucam.org/~sdh31/misc/destroy.html