I have one depressed friend. Anytime I visit him, it eventually turn into a Youtube party. This tendency is by far worse than with any of my other friends.

I'd love to track my personal wellbeing, right now my only metrics are "am I hooked to some flash game or not" and "did I go jogging this week or not". Tracking my web surfing could give something in like "it seems you're having a lousy afternoon" which would be more handy because I might snap out of it.