Sudoku, according to Wikipedia is a "a logic-based number placement puzzle". So what happens to Sudoku when you remove the logic from it? The answer is simple: it becomes a voice mail menu.
I have now access to four different voice mail systems: one at the firm, one at the college where I teach, one on my cell phone, and one at home. Consider the two most frequent functions: play a message and delete it. All four systems have different numbers assigned to these functions. Here's the matrix:
At home: 5 to play; 6 to delete
At firm: 2 to play; *D to delete
At college: 3 to play; 7 to delete;
On cell: 7 to play; 3 to delete
Two systems have opposite functionalities. Pressing 3 at my college's voice mail system will play a message; on my cell phone it will delete it.
Voice mail systems today are just elaborate mp3 players. It's all software. It should be easy to allow a user to determine keypad functionality from a web-based interface. Why is this not happening?