Funny how it only goes one way. Not many employers are OK with someone taking Friday off because they got their work done early. Lots of employers will see nothing wrong with asking people to come in on the weekend. I think people forget that the employer/employee relationship is a value for value business relationship. As a professional I'm flexible but I'm not exploitable.
Taking a salary means you are being responsible for what you achieve, not just mindlessly churning out the required number of hours.
Taking a salaried work means you are being responsible for the well-being of your employees, not just mindlessly handing out fixed amounts of money.
But for some reason rush hour starts just after noon on Fridays (at least in the bay area). So many employers seem to have some flexibility.
I'm paid a certain amount to do a job, with technically unspecified hours, although with the cultural expectation that it'll be 40 hours per week. If I'm going to spend a few hours with a customer (presumably part of my job, in this hypothetical situation), I'll expect some flexibility next time I've got a couple hours of errands to run during the week.
I'm not so worried about one-off occurrences, but I'll take exception if I start to see a pattern of my hours inching up. 42 hours a week? Doesn't sound like much (24 minutes a day). What do you think would happen if I asked for a 5% raise for 5% more work? Right now, my manager would tell me that we don't have the budget, and his manager would start probing around to see how to spread out my current workload to other employees.
Staff attorneys / in-house counsel are generally salaried and work as described above.