Spell with Flickr can be used with vocabulary and spelling lessons, and used to produce unique graphics for a variety of multimedia applications.
Motivational Poster Generator
This can be used to develop posters for many different content areas (character posters, setting posters, history, science - you name it).
The images generated in this site can be used in blogs and wikis. They can be saved as pictures and then used in powerpoint, on print and other applications.
In my wiki, there is a page called Media Making Tools. I have started creating a pathfinder for different tools for multimedia. I've added these tools to it. I invite you to add to the wiki - it is now unlocked.