I recently posed a question on arranging 10 queens to make a Petersen Graph. It was solved on the 5x6 board by Daniele Degiorgi. In what is sure to become a beautiful defining example, Geoff Exoo arranged 14 queens on a 7x7 board to make the Heawood Graph. It can also be seen as a Fano Plane. For those that wish to tackle this problem, arrange seven black and seven white queens on a 7x7 board such that for every like-colored pair of queens, there is exactly one queen of the other color that attacks both. Also, no queen attacks another of the same color. Answer here: http://ginger.indstate.edu/ge/COMBIN/QUEENS/index.html A different problem: the smallest solution for N^2 queens in an NxNxN cube is N=11. A solution is at the following link: http://www.csse.monash.edu.au/~lloyd/tildeAlgDS/Recn/Queens3D/ --Ed Pegg Jr