The AAPT Photo Contest
The American Association of Physics Teachers (AAPT) runs an annual high school physics photo contest. The contest is open to all high school students in grades 9-12. There are several categories in the contest - including Natural Photos, Contrived Photos, and Photos with Multiple Images. The official description of the contest, the contest rules, the entry forms and photos from past winners can be found online at the AAPT website.
The Physics Classroom encourages high school physics teachers to promote the event among their classes. Consider offerring students extra credit or a homework pass for particpating in the contest. Or simply make it an assignment that all students participate in. Since only 15 photos per school are allowed to be entered, you could conduct a local contest and the top 15 winners could be submitted. Consider uploading your students' photos to your Flickr photostream and then adding them to The Physics Classroom Flickr Group. Your students might enjoy seeing their photos appear as thumbnails within the various pages of The Photo Gallery.
Visit AAPT Photo Contest page.