why is the sky dark at night ? (aka Olbers' paradox)

as i was reading stephen hawking's "universe in a nutshell" (in small bursts, while waiting for perusu in juniper's parking lot), i came across this seemingly simple question, which is also known as the olbers' paradox! and intially, i was stupid enough to think that this is very easily explainable, like its because we are in the side of the earth not facing the sun and that the stars are "sort of" :-) far away and light scatters/disperses due to distance/cosmic dust... :-( but then, it was amzing to read that the answer to this question gives raise to some clues to the origin and age of our universe...

the paradox: If the universe is assumed to be infinite, containing an infinite number of uniformly distributed luminous stars, then every line of sight should terminate eventually on the surface of a star. The brightness of a surface is independent of its distance, so every point in the sky should be as bright as the surface of a star.

and here's a very brief answer :

1. the universe is young - we haven't had enough time for all the lights from the all the stars to reach us...
2. the universe is expanding - and so stars are moving away reducing the intensity as well as the amount of light that reaches us, as time increases...

http://spaceplace.nasa.gov/en/kids/phonedrmarc/2002_december.shtml
http://en.wikipedia.org/wiki/Olbers'_paradox

and this one is for the geeks...
http://zebu.uoregon.edu/~imamura/123/lecture-5/olbers.html