The Sudoku page has been improved today. When entering a number, some simple checks are made for an error. If the number entered is OK, it automatically moves to the next cell ready for another number to be typed. I updated the server application also, and the solution can be interactively solved. The server now solves easy parts of the puzzle as you key it in. This is implemented using AJAX programming techniques.
I would also like to set up a daily puzzle. The Pascal source code for the server side solution engine might get posted, if I find time to tidy it up. Please leave comments if you have any ideas!