Super short post, so foul on my part.

A friend (NR) recently told me about MoodViews, which uses pulls various bits from blogs and aggregates them. I have not played with the site too much, but it seems interesting (but probably not much beyond that since it is so limited). From what I have linked through, it focuses on pulling the current state (e.g., happy) from bloggers and tracks changes in those states.

If this up your alley, it is worth a five-minute poke through.