Indicators, my pet hate. The number of times I am following someone on a vmcc run and they leave them on for mile after mile after mile.
I was a witness to an accident caused by a lad on a modern bike forgetting to cancel his indicators. I am now very aware of the problem.
I've sometimes rushed ahead to overtake a rider who has forgotten their winker. When I let them know, they sometimes look at me as if I should not have bothered. 
Trouble is, most new drivers do not seem to understand hand signals and do not seem to appreciate that not all vehicles on the road nowadays have indicators fitted.
In the interests of safety I have decided to fit indicators of my Sunbeam which I use as well as hand signals. I do have a warning buzzer fitted which gradually gets louder the longer they are on but even so I have to admit that I have sometimes forgotten to cancel them.
This is a worry so I will be fitting one of these
http://www.safer-turn.com Quite a clever piece of kit which cancels the indicators after a turn. According to the blurb, they have a gyroscope inside which indicates lean.
The reviews are pretty good.
They also sell a gadget which senses deceleration and automatically flashes the rear brake light.
Not cheap but what price safety?
Jim