Othar Tryggvassen has a Twitter. It's a mostly day-by-day account of his adventures as a professional hero. Full of lines like "Have noticed that Spooky is staring at me. Follows my every move. Unnerving. Ate some cheese."
I love stuff like this. Square Zero has something similar--the characters post in the comments section. Which is weird, especially if you've read Schism, the webcomic it's based on. (And which I wish would update. Hasn't in ages, but when it was updating I liked it a lot.) They'll often have these odd, extended arguments with people. I don't know if the author already knows these people, or if they're just random, but either way, it's cool.
Having characters interact directly with the fans of a production is cool. It's the sort of thing that works especially well with webcomics, and other web-based media. The reader space is less formal, and it's easier to get from a webcomic to whatever forum or blog you're using. Not a bad marketing technique, really. Especially when done on a social type site, like the Othar thing is.
But what would be really cool is if the character interaction system was the whole point. Say you had a blog, or a series of blogs, and they interacted with each other and with the audience. There could be some kind of plot, and it could even be set in some world other than mainline Earth, but you'd also have the audience interacting with the characters in more or less the same format that the characters interacted with each other. Be a bit like roleplaying.
I need to get on this.