Square Numbers

I LOVE this lesson at Childplay about square numbers. What fun! It's on my to-do list. When we do the lesson, I'll add the book, Sea Squares, in which "Rhyming text and illustrations of such sea animals as whales, gulls, clown fish, and seals provide opportunities to practice counting and squaring numbers from one to ten." (from book summary)

What lessons have you done with square numbers? Post your link! ;)