Here is a great tip from the most recent Gentoo Newsletter:
Using TODO lists with your shell
Love the shell? Want to know what else you can do with it? This tip is for you!
An old issue of the GWN featured a tip on using app-misc/devtodo. It's great for creating TODO lists, but what about keeping track of them?
If you set PROMPT_COMMAND="todo" in your environment, the TODO list of the current directory (if there is one) will be displayed before every shell prompt.
If you use PROMPT_COMMAND="todo --global --global-database ~/TODO; todo" you will see your global TODO list followed by the current directory's TODO list. This makes keeping track of your tasks much easier.