The question on the tricky puzzle page is: Using the rules established for the simple puzzle, can you solve this puzzle? The answer is "no." It's impossible. The "other" answer (provided by Shane Eaton) is that you can solve it as long as you don't use a pencil, since the instructions only say that you can't lift your pencil. I liked that that answer because it also implied that the puzzle was otherwise impossible, which indirectly answers the question, "can you solve this puzzle?"
This space will eventually contain an explanation of why this puzzle exists, how different people approached it, etc.