Photography Contests in the Yahoo! Directory

Worth1000.com
Includes daily contests where those participating get to corrupt and play with images to create interesting pictures in Photoshop.
www.worth1000.com
Digital Photography Challenge
View and vote on, or compete in, bi-weekly digital photography challenges. Includes forums, photographer profiles, tutorials, and more.
www.dpchallenge.com
PhotoshopTalent
Weekly contests of advanced Photoshop artists' work, and also provides a database of Photoshop tutorials.
www.photoshoptalent.com
American Baby Contest
Baby and child photo contest. Judging fee and prizes for quarterly winners.
www.americanbabycontest.com
Nikon Small World
Photomicrography competition showcasing the beauty and complexity of life as seen through the light microscope.
www.nikonsmallworld.com
International Photography Awards
International photo contest for professional and amateur photographers using both digital and traditional mediums.
www.photoawards.com
PhotoshopContest.com [read review]
Take a pre-chosen image, alter it how ever you like and post it for others to view, vote, comment, and submit their own versions.
www.photoshopcontest.com
Freaking News
Actual news stories fuel Photoshop contests of wacky doctored pictures with an emphasis on political and strange news.
www.freakingnews.com
Visions of Science Photographic Awards
Competition sponsored by The Daily Telegraph and Novartis. Includes galleries of past winners.
www.visions-of-science.co.uk
Sport Movies & TV International Festival '99
Organised by Federation International Cinema Television Sportif (FICTS), awarding prizes for films or photographs of any sporting event.
www.sportmoviestv.com
Photos of the Year - Digital Photography Contest
Offering digital photography contests, discussion forums, and DSLR camera and digital stock photo galleries.
www.photos-of-the-year.com
World Open Underwater Photographic Competition
Winning images will be placed on postage stamps of the British West Indies.
www.underwaterphoto.com
EPIC
Environmentally aware photographic competition.
www.epicphotocontest.org
National Geographic International Photography Contest 2009
National Geographic's International Photography Contest draws thousands of spectacular photos of people, places, and nature from users around the world. View galleries of past competitions.
ngm.nationalgeographic.com/photo-contest/photo-contest
National Photo Awards
Monthly and annual contests awarding cash and prizes, with divisions for amateurs and professionals. Competition is open to photographers worldwide.
www.NationalPhotoAwards.com
Everyman Photo Contest
Aims to showcase the amateur photographer's occasional flash of brilliance.
www.theeveryman.com
Photo Laureates
Photography contest where amateurs benefit from the feedback of senior photo competition editors and get a chance at exposure and recognition.
www.photolaureates.org
KidKontest
Offers a photo contest with weekly and monthly prizes.
www.kidkontest.com
London Photographic Awards
Galleries of previous years award winners, photographers portfolios, photo essays, online photography exhibitions, and details on how to enter the current competition.
www.london-photographic-awards.com
MysteryPhotos.com
Identify the object in the photo to win prizes.
www.mysteryphotos.com