Google Goggles Does Sudoku
Image recognition software aside, the interesting mathematical idea here is how one would create a computer program that can solve an arbitrary Sudoku puzzle. It doesn’t seem like a particularly challenging task, but finding an efficient method may be a challenging problem. After all, I imagine some strategies are better than others.
Experienced Sudoku solvers probably have a general algorithm they follow, but I imagine that intuition (guessing?) plays a role at some point. Can you program that in somehow?