Professor of astronomy and physics, Guillermo Gonzales (privilegedplanet.com(1)), discussed the odds of life in the universe and explained his Privileged Planet hypothesis. According to Gonzales, the places in the universe that can host intelligent life (like Earth) are also the best places for viewing and analyzing the universe. He believes such "privileged" places are extremely rare in the universe.
To prove his point, Gonzales refactored the Drake Equation -- a mathematical method to determine how many intelligent civilizations are in our own Milky Way galaxy. After citing a less than 1% chance of intelligent life Gonzales concluded, "In my opinion, we're alone in the galaxy." He went on to say that while there could be as many as one billion civilizations in the rest of the universe, "we're probably alone."
Gonzales asserts that the chances for intelligent life increase greatly if the universe was designed. This is because "the Designer would have created the conditions for life on other planets." This does not necessarily mean there are other civilizations, but it certainly opens up more possibilites than a purely materialistic view of the universe, Gonzales said.

1. http://www.privilegedplanet.com/

Anthropic Principle

In 1973, astrophysicist and cosmologist Brandon Carter of Cambridge University proposed the Anthropic Principle, a theory which attempts to explain why our solar system seems to be finely tuned for intelligent life. That is, the universe gives the appearance of having been specifically designed to allow for human life on planet Earth. In their book The Anthropic Cosmological Principle(1), John Barrow and Frank Tipler define the most basic form of this concept:
"Weak Anthropic Principle (WAP): the observed values of all physical and cosmological quantities are not equally probable but they take on the values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirement that the Universe be old enough for it to have already done so."
Barrow and Tipler further proposed the Strong Anthropic Principle (SAP), which states that the Universe had to bring humanity into being: "The Universe must have those properties which allow life to develop within it at some stage in its history."
Some astronomers explain the fine-tuning of the universe as a result of chance. However, in "Home Alone in the Universe," Guillermo Gonzalez and Hugh Ross argue, "By insisting that the apparent fine-tuning of our solar system's parameters is just due to chance, rather than pointing towards a greater truth, astronomers have missed out on many discoveries."
Sources:
http://ourworld.compuserve.com/homepages/rossuk/c-anthro.htm
http://www.physics.sfsu.edu/~lwilliam/sota/anth/anthropic_principle_index.html
http://www.firstthings.com/ftissues/ft0005/opinion/gonzalez.html

1. http://www.amazon.com/exec/obidos/ASIN/0192821474/ctoc/104-2720055-5891967