Here are some nifty websites I've discovered that might help you with your vocabulary posters:
Shahi - A visual dictionary that searches Flickr, Yahoo, & Google for images
Visuwords - A graphical dictionary that shows how words and their meanings are linked together
Brainyflix - A website with words and videos of common SAT words. Great fun!
Wordle - Create a cool word cloud from your blog or any piece of writing
FreeRice - Addictive SAT word quiz website. Get correct answers and win rice for people in need.
Flocabulary - SAT words put to hip-hop