It won't happen again until December 2117. On June 5th, 2012, Venus will transit the face of the sun. The best places to watch are in the mid-Pacific, but travel is not required. The historic event is widely visible around the world, including at sunset from the USA.
FULL STORY: http://science.nasa.gov/science-news/science-at-nasa/2012/18may_venustransit/
VIDEO: http://www.youtube.com/watch?v=-nXv9YvkNyA
