MD80 Captain reports inattention by a Guide man during taxi into a gate. Guide man was walking away and talking on a cell phone prior to the aircraft being aligned with the self parking system.

Narrative

Arrived during bright morning sun (rising). As the sun shone just above the terminal (east facing taxi); seeing the guide man was made difficult as he stood back in the shadows of the building. With the combination of bright sun light in our eyes; and both sun visors extended downward before our faces; my First Officer and I (both) continually leaned forward as I maintained the yellow stripe in view while it slowly was passing under the aircraft's nose. I vigilantly checked my left wing (ERJ parked to left side) and peered cross-cockpit (to the right side for GSE) during this slow taxi. As we approached the (right) turn into the gate (now the nose of the a/c in the shadows); we observed the guide man walking away and talking on his cell phone. It would have been preferred that more patience and assistance be provided throughout the taxi turn into the gate line. I would like to suggest that a guide man continue to provide assistance to the Captain during a taxi phase (which is ultimately regarded as the Captain's responsibility) until the aircraft is parked; or that time which the Self parking guidance system becomes the primary guide. In this case; the guide man left his duty early. Additionally; I would recommend that cell phone use be limited in ramp areas where an employee may be critically injured (or even worse) when distracted by it's use. It is not uncommon to observe ramp personnel with cell phones wedged under earmuffs (field-made; hands-free devices) during ramp operations.