I have 5 identical ti-tac-toe alphabet books that I was given by a friend.  On each page, it has 2 letters of the alphabet with nine tic-tac-toe boards.  The idea is that by playing the game with letters rather than the usual x's and o's, children will become more familiar with the alphabet.  On the last page, you are encouraged to try to spell words on the tic-tac-toe board.  The books would be good for a preschooler or kindergartener to do when they are bored.  They could be done with a parent, or even a sibling or friend. 

Tic-tac-toe is also a great way for children to learn strategy.  My children have eagerly studied every possible way to win, and usually beat all their friends.  My oldest daughter even researched tic-tac-toe strategy online and learned alot of interesting math concepts.

If you would like one of these books, I will send it free with any order from my shelf.  Please PM me.  Thanks!