There's a lot of talk about how social media might revitalise politics. And a lot of attempts by polticians to use social media to circumvent the press and broadcasters and reach the public direct. So I wasn't surprised to see 10 Downing St using Twitter to send out messages from their press office. But I was surprised to see them respond to questions via Twitter - it seems to be genuinely two-way. Good for them, I hope they manage to keep it up.