A project that I have had students do in the past is to create a "Wall of Fame" for Black History Month. I have students do reports on an African-American man or woman and then trace an image of that person's head to create a silhouette. The silhouette and report are then displayed down the hallway for a dramatic "African-American History Wall of Fame." Parents and students love this. After browsing the Picnik site, I ran across this YouTube video on making silhouettes from images/photos found. It might be a great way to implement this technology tool into this project!
Other photo editing apps:
This photo was created in Dumpr using the Rubik's Cube effect.
I really liked BigHugeLabs. One of the tools allows the user to create a Movie Poster. I can see my students using this application to create posters for book reports, author studies (Students create a poster about an author.), during Women's History Month in March, students could create a poster about a famous woman in history. I created this image using the Movie Poster tool in BigHugeLabs.
Another tool from BigHugeLabs lets you create a Magazine Cover. Like the Movie Poster, this could be used by students to create covers for any subject being studied.
Not only are photo editing tools great for classroom use, I believe photo editing can be easily used for personal use! Creating invitations for birthday parties, images to be used in scrapbooking, calendars, etc...again, so many possibilities!