A couple of different challenges, for example 2009challenge which is one theme a day.
URL: http://www.photochallenge.org
Challenges
"PhotoChallenge.org"
2009-11-03 17:33 
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"Lens day"
Weekly photochallenge based on a theme. New challenge posted every wednesday.
URL: http://lensday.com
2009-11-03 17:27 Write a comment » 
Tags: wednesday
