I have a visual puzzle done it tikz for the 5th. It's functional, but artistically underachieving. Are there any budding artists out there who might like to produce a prettier version?
(As I understand it, it is now de rigeur on the Internet to add: "I can't pay you, but think of the exposure.")
@PDT Hah, perhaps that was a typo? I see no bounty specified so it looks like it may have been an error. Can you edit the spreadsheet, or would you like me to edit anything in for you?