Here is a link to an article about astornomers prediction of soon finding a twin to planet earth in our galaxy.
http://www.msnbc.msn.com/id/25350155/
This is not some crackpot "National Examiner" story but a legiimate news story from esteemed astronomers.
Of course anyone visiting a planeterium should leave realizing just how small the earth and our solar system is in the universe and that surely there must be other earth like planets among all of the trillions of stars.