For anyone on Twitter a useful quizzing account to follow is @twiznight
Twiz Night has been running for a number of years in Ireland and is basically a twice-weekly prize quiz on Twitter. Its a clever business model in which companies offer prizes for exposure and hash tags and it all benefits the player who simply logs in and answers a few questions! The whole quiz lasts about an hour or just under and it is judged not only on your answers but also on the speed at which you answer.
Works much better than you can imagine and usually is quite a fun and active night of quizzing.