Originally Posted by greenstork
Continental Sport Contacts 26x1.3"
I've commuted on these and can't praise them enough, although virtually any smooth 1" - 2" tire will get him started. If I were you I'd also set him up with Mr Tuffy liners, spare tube, patch kit, levers, and pump, regardless of what tires you decide on.
Also if he has never done it let him change one of the tires so he'll have a degree of confidence if/when he flats.
You've earnt a whole bunch of good karma points for helping someone deiscover the joys of cycle commuting, good for you.