Cruise Control 
 
This mechanical cruise control proves the old adage that the simplest things are usually the best!
It simply clips around your twist grip (pic 1) and when you have found the speed you wish to travel at, using your forefinger,  just twist the control around until it rest on your brake lever (pic 2). The grip is then set in position until you  open or close it yourself. Front brake operation is unaffected.
Dead simple and effective!