German designer Fabian Brunsing created a very unique Pay & Sit Private Bench specially for those who hate sharing their seats in a park.
In a normal state, the bench is all covered with metal spikes. If you want to sit and not hurt your rear end – you have to slip a 50 Euro cent coin (~66 cents US). Than the spikes retract, and you can comfortability sit for a fixed period of time before the alarm goes off. Few seconds after the buzzer spikes rise again.