If anyone lives near Houston...Texas Freethought Convention and American Atheists is throwing a 'rapture' party: http://www.eventbrite.com/event/1587866351/efbnen
We also have a little park get together going on in DFW that day sponsored by http://www.DFWCoR.org groups: http://www.facebook.com/event.php?eid=195152620516168
If you know of any other atheist rapture watch parties list them here
For the theists: we don't actually think anything is going to happen, it's just all in fun.