Buy & Sell Waiting Time
Time is money, but for different individuals it has a different value. Bill Gates for example (or a busy manager) will lose hundreds of dollars in the doctor's waiting room or while he is standing in a long queue at the supermarket, while a student's time is much cheaper.
My idea is that you should be able to buy / sell your waiting time. If you're in a hurry and don't want to lose valuable time, you should be able to buy time in situations that would otherwise be time-consuming. Selling their time would also be an interesting source of income for people who are not so well off.
Of course, some (central) agency would probably have to coordinate this.
Reward: A certain amount of free bonus time at my disposal.