The process feels to me like a mixture of writing, acting and showing off. Maybe that's how improv feels? I've never had the courage to try anything like live improv (let alone the talent).
I'm also finding that tweeting my character @cynpa, while tweeting in my own right as @pilchard7, while getting on with my day job, is not as confusing as I feared it might be. I think this is because tweeting is a bit like day-dreaming. I can slip into Cyn's head and gaze out of her mental window for a few seconds, capture her thoughts, and send them out into the world we're sharing for the duration of this experiment. Admittedly, it would be harder to juggle these activities if I had a proper job that involved steering something, or cutting somebody open, or giving a damn about real people in real time.
Which leads me to ask... Is Twitter for writers? Are people who like Twitter all writers? Is Twitter the saviour of literacy? Traditionalists line up to spank technology as a force for dumbification, but maybe they ought to take a longer look at the Twitter phenomenon. It's not about celebrities - it's about voices... Voices that want air.