Valentino Rossi's finger-operated rear brake
Peter Bom: To be able to apply the rear brake deep into right-hand turns (where space to operate the foot pedal runs out), some riders are experimenting with the idea of operating the brake with one or two fingers of the left hand. Valentino Rossi is one of those riders, trying the system at the Monday test after the Barcelona race. The current state of technology in MotoGP, and especially the type of tires being used, makes using the rear brake crucial at various points around a circuit. The rear brake is used particularly to help the bike turn mid-corner. The question is now whether we will see more riders use finger brakes, and at more points in the track.
Spirit level on Dani Pedrosa's rear wheel
Peter Bom: A spirit level in the rear wheel, at a right angle to the direction of travel. Never seen one before or heard of one being used outside of endurance racing, where the wheel stand is asymmetric to be able to stand the bike up horizontally in a pit lane which is not horizontal. I would take an educated guess that the MotoGP teams use a spirit level to ensure the rear wheel is horizontal to be able to zero out the accelerometer sensors, especially the lateral sensor.