It’s well known that it’s not okay to text while driving, and presumably the same should apply to tweeting, checking email or most other cellphone interactions. But what about checking driving directions or looking at a map? After all, lots of cars have built-in navigation systems, and plenty of those are touch-controlled. It’s still not allowed, at least not in the Golden State, according to a California appeals court. The court ruled that hands-on use of a cellphone is against state law — even to check one’s maps. “Because it is undisputed that appellant used his wireless telephone while holding it in his hand as he drove his vehicle, his conduct violated Vehicle Code section 23123, subdivision (a),” the court wrote in a late March ruling.