If you've been waking up feeling like you might have been fighting off a zombie horde in your sleep, it might be time to start tracking your sleep patterns to get to the bottom of things.
iSleepDiary is a simple question-driven logging tool. Create a free account, answer a few questions every day about your quality of sleep and sleep-related aspects of your day, and soon you'll have a chart you can use to track patterns.
They supply a basic battery of 11 questions, you can add your own or delete them all and create your own set from scratch. To help remind you to fill out the questionnaire every day, they have a handy homepage-forwarding service. Using the guide they provide you can set it up so that once a day when you launch your favourite web browser, you'll be sent to your iSleepDiary account to fill out the questionnaire. Upon submitting it you're forwarded to your normal home page.
Have your own favourite tool for tracking your sleep? Let's hear about it in the comments.