If you've got a file called todo.txt on your computer right now, you're in the right place. Countless software applications and web sites can manage your to-do list with all sorts of bells and whistles. But if you don't want to depend on someone else's data format or someone else's server, a plain text file is the way to go.

Problem is, you don't want to launch a full-blown text editor every time you need to add an item to your to-do list, or mark one that's already there as complete. With a simple but powerful shell script called todo.sh, you can interact with todo.txt at the command line for quick and easy, Unix-y access.