I just came across a new website,
YawnLog, that lets you keep track of your sleep patterns.
You set a target number of hours per night, and then each day, plug in how many hours you actually slept. You can also make notes about the quality of your sleep, your dreams, etc. The site calculates how much you're sleeping each day, and tracks your sleep debt as well.
It's an incredibly easy to use interface, I set up an account and entered my data for last night in about 5 minutes. Here's
my profile, in case you're curious.
I know it's not uncommon to keep journals, diaries, or logs for a number of health conditions, but this is the first site I've come across doing this specifically for sleep. Have I missed some obvious ones? Let me know!