Tomorrow June 5 2012 will be the "Transit of Venus", where the planet Venus appears to move across the face of the sun. The next one will be in 2117.
This event is considered to be unrelated to the impending December 2012 Mayan apocalypse
Don't look at the sun, you'll go blind. (for those that really needed to be reminded)
http://www.transitofvenus.org/" onclick="window.open(this.href);return false; has info on the transit.
Edit - here is a good video of the transit http://www.youtube.com/watch?v=4Z9rM8ChTjY&hd=1" onclick="window.open(this.href);return false;