Some of the best things I've done at work on our system is because I needed it to do something*. A good one was letting you rename mail folders. A more recent one was adding a "Your password will expire in x days" message.

Wade.

* Someday I'll wax long and lyrical about what it does and why it's the greatest thing since sliced cheese, but for now it should be enough to know it's a groupware product run as PHP pages on an Apache server. :-)