The aircraft that my company leases are all charged "take off to landing" this way there is no proffit to the pilot leasing the aircraft to rush the checks or take off with a stone cold engine.
In the long run it is better all round but Occasionaly I do get people being very economical with the truth over flight times. The thing that gives them away is the fuel burn.
I am thinking of fitting the loggers that glider pilots use to give my customers "by the minute" billing, i am sure that it would save the honest guys who lease my aircraft a £ or two when they log to the nearest five minuites and would catch red handed the occasional joker who thinks he can have me over.