"The only gamble that works"
Quiz master machines used to work for us. Three of us used to go from work to the pub every Friday lunch time and used the Quiz master to pay for our lunch and beer. Between the three of us, we covered everything from science, history, politics and general knowledge. The machine also only had a finite number of questions so we quickly picked up the correct answers to the more obscure questions like "How many cups of tea are drunk each week in the house of commons".