At work this morning, several of us were in the break room waiting on the first pot of coffee to finish brewing. One of my co-workers, a project manager, was especially anxious. She said she had checked her email first and really needed to get back to her desk. I remarked, with humorous intent, that the only way that could have sounded worse would be if she checked it on her Blackberry. She agreed, said that her husband had given his back, and that it wasn't conducive to her personal life to have a boss that would email her at 10:30 on a Friday night and expect a nearly immediate response.
I recognize that I have a responsibility, indeed an obligation, to be available for application coverage. That's been part of my professional reality for over 20 years; being on-call is part of a programmer's job. Sometimes that requires, for a short period, 24/7 availability.
I reject the notion that a corporation has any more of a claim than that on me, not without a lot more loyalty and commitment than the workplace gives any employee these days.