I'm lucky there, mines mainly Monday to Friday only rarely at the weekend, although even when I'm not at work I'm on permanent call and have to answer some mails via my BB and pretty much always be available within reason.
Dealing with people in Australia and Korea at the moment so get mails at all hours, still I always remind my self of the days when i worked in a freezer warehouse starting at 5:30am and finishing at 2pm for little more than a minimum wage, so what I do now has to be better than that.