I've done this bulletin board every year, and the kids (and adults) love it! I send out a letter to the parents asking for random items, and this is what I got this year:) The item to search for changes every day.
Interactive vocabulary bulletin board - image only. I could totally use this, when kids turn in all their HW in a week or finish all their classwork, they would get a letter, and they can save the letters until they make a word
National Poetry Month idea? Have a container full of words (nouns, verbs, adjectives, etc.) and also residents to mix and match them. They could be hung by pins or Velcro. Perhaps once a week residents could vote for their favorite poem?