I think puzzles would be great for the site.
"Code golf" questions pop on stackoverflow all the time. These questions challenge users to write code that successfully accomplishes a task in as few characters as possible. For example, Write the shortest program that implements John H. Conway's Game of Life cellular automatonWrite the shortest program that implements John H. Conway's Game of Life cellular automaton. (Mathematica can do this in 151 characters, amazingly!)
This sort of thing actually can be very educational and interesting. Even seasoned programmers can learn a lot from seeing other people try to work out solutions to problems in novel ways.
Similarly, physicists shouldn't get too haughty and start to believe that they know everything, and certainly not that they know every method. You can learn a lot from seeing how other people approach problems. Mechanics around a rail tank wagon is an excellent example of this.