The locking guitar strap is a guitar strap, which can be securely attached to the button of a guitar or other stringed instrument by means of a locking mechanism mounted internally into the end tab of the guitar strap, thus preventing damage to the instrument by accidental disengagement of the strap from the instrument. The control system includes a plurality of buffer memories for temporarily storing optical data from documents processed through the scanning station, and a control circuit connected to the buffer memories and the document feeding device. The PC card slot is formed in the front panel or the like of the CCU. The invention also encompasses methods to produce polypeptides that possess abrogen activity as well as method for using these polypeptides. In these embodiments, Applicants’ power source further comprises a rectifier, and a charge return path interconnected to the piezoelectric element and to the rectifier, wherein the charge return path conducts electrical charge to the piezoelectric element to prevent depolarization or stiffening from occurring after repeated cycles of piezoelectric charge generation.