Drakes Theorem states there should be at least 6,000 other civilizations in our galaxy. We should be building starships like we build trucks, but cutting through the bureauracy and secrecy is the hardest part. Even the president refuses to confirm or deny the existence of extraterrestial beings and their spacecraft.
Drake Equation:
http://en.wikipedia.org/wiki/Drake_equation
DARPA(Defense Advanced Research Projects Agency) funded this creation, the "100 Year Starship" Project :
http://100yss.org/
Recommended reading:
http://www.amazon.com/An-Introduction-Planetary-Defense-Extra-Terrestrial/dp/1581124473
just my .02 cents