Here's a fun hands-on puzzle.
Take out a sheet of paper, and divide it into nine squares. Label each square with the letters above. It might help to label the back of the squares too. Next, crease the paper along all the lines. Now it's time to do some complicated folding and tucking!
The idea is that you fold the nine squares down to a single square. The top square should be an S. The next square underneath should be a P. The next should be an I, and so forth, until you've spelled the word "SPINELESS". If you do it right, maybe a squid will appear when you unfold it?
If you figure it out, it might be too difficult to describe each step of the fold, so it should suffice to tell me how the E's and S's are ordered.
The "spineless" puzzle is my own creation, but it was inspired by a similar puzzle created by Robert Neale. I only created my own mostly because it was a fun challenge, but also because Neale's puzzle is a tad more difficult.
Using this paper, you must spell the eight pseudonyms of Beelzebub: Bel Zeebub, Bub Blezee, Ube Blezbe, Bub Zelbee, Bub Beelze, Zee Bubble, Buz Lebeeb, Zel Beebub. The final challenge is to spell his real name, Beelzebub. If you do it right, maybe the fallen angel will appear when you unfold it?
See my explanation of how to find the solution (actual solutions not included)
[For further reading, see "The Combinatorics of Paper Folding" in Martin Gardner's Wheels, Life, and other Amusements.]