I read the comments everywhere I go. I read the comments on my sites, I read the comments on the sites my companies work on.
I find myself wanting to write about things just to connect in some truly random way with other folks that frequent the sites I go to.
I know Google's not the first to do something like this, but they've gone at it from the other end--taking existing content and making it visible, as opposed to forcing people to write/leave comments _through_ their software. The power of search. :)
For instance, my post on storyhouse.com's demise is up at the top of the comments on that site at the moment, and will be pushed down over time. I randomly went to another person's blog who had posted something about submitting something there and left them a note, on the likely chance that they hadn't gotten around to checking back themselves. There's still quirks, of course. My post is actually on www.storyhouse.com and not storyhouse.com. I'm deliberately posting to the other url with this one so as to cross-pollinate. And I've had some really odd things turn up where google was guessing somedomain.com.bz's comments were applicable to somedomain.com's site. ((odd that they'd do postfix, but not prefix subdomains--I'd think it would check ip or something, since they can spare a few cycles...))