My daughter emailed me this brain teaser, called Funny Farm, and I think this is the best one I have seen. Use this link to look for the Funny Farm Puzzle.
We've been working on it for over a week now. It's fun and great to do with someone else. My daughter started it with her whole work team over the Memorial Day weekend holiday, and they finally finished every single answer to complete the entire grid. The idea is to guess the answers in each mini-grid and open up the other grids as you go. Great word fun, and addictive! Have fun.