Just saw a link to this, which is a project between the national media museum and the University of Cambridge.
I didn't allow it to access my facebook profile because I don't let anything other than friend access that, but I was surprised at what it had gathered from my answers to 5 questions.
Although... having said that, I had to pretend I would follow Richard Branson on the Twitter and Red Hot Chilli Peppers for streaming music. In reality, nobody on the Twitter list really interested me and the Chilli Peppers was a band I'd previously have listened to, but they seem to have sunk down my listening preferences. They were just the least unlikely answers for me.
Have a look and see how accurate your online reflection is - I imagine it's only accurate on the basis of sweeping generalisations.
I disagreed with "Few friends" in extraversion - just well chosen ones. "Aggressive" in Agreeableness is also inaccurate.
69% Openness: Intellectually curious you appreciate beauty wherever you see it. You may consider yourself to have a vivid imagination which makes you more creative than most. On the web, you're quick to try new sites but will also quickly move on.
Words that describe you - curious, creative, sensitive, individualistic.
71% Conscientiousness: Someone who avoids unforeseen problems by planning ahead. You work hard and are reliable. You value the Internet because it helps you increase your productivity - you're unlikely to waste time browsing aimlessly.
Words that describe you - careful, organised, hardworking, perfectionist.
40% Extraversion: Someone who prefers low-key occasions with a few close friends. You aren't afraid of large parties - you just don't enjoy them. The web gives you the chance to spend time with people who share your interests in a less pressured environment.
Words that describe you - introspective, quiet, independent, few friends.
49% Agreeableness: Someone who gets along with others well - especially once they've proved themselves to be trustworthy. You have a healthy scepticism about others' motives although you basically consider them to be honest and decent. Online you probably avoid controversial issues unless they're particularly close to your heart.
Words that describe you - competitive, assertive, plain speaking, aggressive.
69% Stability: Calm and emotionally stable. Very little bothers you and when you are upset it's not for long. When online you don't wear your heart on your sleeve because you're too busy doing things.
Words that describe you - relaxed, calm, stable, positive.