Answer courtesy of the windows calculator:
= 1,000,000,000 seconds / 60 seconds = 16666666.66666666 minutes
= 16666666.66666 minutes / 60 minutes = 277777.777777 hours
= 277777.777777 hours / 24 hours = 11,574.07407 days
= 11574 days / 364.25 days = 31.77508 years!!
..and that is just a billion. So a billion seconds ago it was 1976, amazing. Like I said, a billion is big, now think of all those bits on your 30 gig (billion) music player! It's a wonder you don't grow old waiting to play the music that is on it. ;)