http://www.aday.org/
You have one day to join thousands around the world in using the power of photography to create, share and compare perspectives on daily life! Don't miss it! You can upload your images until May 22nd.
http://www.aday.org/news/2012-05-12/date
The upload site will open as soon as the first time zone hits May 15, but it is important that you to take photos only during the 24 hours when it is Tuesday, May 15, where you live.