When I have a large deadline looming, I like to keep track of how many days I have left.
I've tried Dashboard widgets, iPad apps, and just about anything else you could think of, but they all have failed for one simple reason: they require me to check them. I can go days or weeks without triggering the Dashboard, and an iOS countdown app still requires that you check it. I could use something like Due app but I really don't want something actively distracting me, I want something passively reminding me. Nor do I want these cluttering up my iCal.
I found my solution by cobbling together several bits of free Unix utilities that are essential to any true geek's tool belt.