A website which solves sudoku. Currenty deployed at http://sudoku-6.apphb.com/
The first (non-coursework) program I wrote many years ago was a sudoku solver, and I plan to convert it into a web-app and put it online, just for fun.
It was originally in C, then shortly afterwards converted to a C# desktop app. This project is to incorporate it in a C# MVC.NET website. I don't plan to refactor the code, just expose it on the web.