I got bored the other day so I made a sudoku solver. It works ok - I thought I'd have to use some clever method to get it to work but the brute force method (trying every valid combination of numbers until one works) takes at most a tenth of second anyway. Ah, modern computers do allow us to be lazy. I wrote it in realbasic so I can compile an OSX version too but unfortunately it uses different fonts so the dividing lines don't match. I plan to change it either to a grid or just a large image and handle input myself.
Also found a good web comic
the other day that nicely sums up Jack Thompson's recent tantrums