My other half has Arthritis and uses a fabulous little device called Easifuel that you just wedge in the trigger.
It costs �2.99 from http://www.easifuel.org/
and is endorsed by several disabled groups.
I work in a petrol station and we don't switch the pump on if the customer is not holding the handle as it is to prevent slop over or the nozzle coming out and causing a spill. It can be a big clean up operation if too much fuel goes on the forecourt and obviously a fire hazard as some people become complacent and think the guidelines are a load of rubbish. Just saves everyone a whole load of hassle if the pumps are used correctly. Also the customer may be obliged to pay for the spilt fuel!!!