I spent almost an hour and a half wondering why I couldn't get a web form to work, and it turns out IT was having e-mail problems and it had nothing to do with my lack of competence with Java Script. I thought I knew plenty to cut, paste, and manipulate, but was getting worried.
Here is a picture of the "Where's Waldo" picture I drew for Harry Potter Night. There's an object hidden in it the students will have to find. I had a lot of fun coming up with every obscure reference I could fit into a single sheet of posterboard. We're expecting this to be the most difficult challenge.