When I lived at home, I'd always call my mom if I had to work late, or was out with friends and running late...I don't have a job now, though, so no need to call my husband and tell him I'll be late...
On his side, he never calls. It used to bug me, since I'd try to make dinner and plan it for when he'd be home, but after a few nights of keeping stuff warm in the microwave and being pretty damn hungry myself, that stopped.
What really gets me is when he goes to LAN parties (every weekend.) Sometimes I want to make "plans" for when he gets home...he'll agree to be home by a certain time, then ends up getting home two to four hours later. I understand it's easy to lose track of time when playing computer games, but yeesh
But, right, back to the thread

I'm almost always ten or fifteen minutes late for stuff--going out with friends or whatever. But if I'm going to be more than 20 or 30 minutes late, I call. Like everyone else has said, it's the considerate thing to do.