Solving Sudoku puzzles

I have recently taken up the challenge of solving Sudoku puzzles. Not that I intend to spend any of my precious free time sweating over a 9 by 9 grid, pencilling in (and subsequently erasing) numbers to complete the pattern. Oh no, not I. I find it much more challenging to write a program that will solve Sudoku puzzles for me.

Now, this is an ongoing project for me. Sudoku puzzles are difficult to solve. In my program, I use a couple of techniques to find solutions, but these algorithms don't solve all Sudoku puzzles. As I explore, I will add more algorithms to the program, and improve it's ability to solve these puzzles.