I seldom leave work completely alone either during the weekend, at night, on vacation, etc. My company happens to have a very flexible policy towards telecommuting and I don't often notice the extra hours I put in.
I'd say my job never ends but that'd be misleading: it ends when I want it to end. As long as certain deadlines are met and I'm available to answer other designer's questions, there's really no time I "have" to work. The flip side that I put in whatever's necessary to get the job done.
I'd say that's a good trade-off. I'd like to think most engineers aren't trading time for pay; they're trading complete pieces of work for pay.
That's pretty much the way I operate too. Conference calls and even webex are easy to do from home or elsewhere, for that matter, and I take advantage of that too.
All the more reason to wonder how long I would stay at Yahoo, if I were one of those unfortunate employees. My question on that score being, if there were telecommuters who didn't perform, why punish the entire company? Just let the bad apples go.
I think the best companies will allow for people to work their 8 hour days and not be penalized. At the same time, companies should reward people who perform at a higher level and do more. Often this means putting in much more time. I also think that it's fair that a person should not expect to rise through the ranks working only 8 hours/day. That is essentially doing the minimum.
Frank makes a good point. While I work more than the 8.5 hours a day an earlier poster mentioned, I also mostly choose my hours and can hang out with the kids in the morning or afternoon before/after going in to work at weird times for global telephone meetings. So you have to measure the overall lifestyle and flexibility, not just when and how much people work.
Work/life balance has always been a struggle for as long as I've been in this profession. I have to say though, I appreciate the benefits that technology has brought us that make it easier to achieve that balance.
In the old days, if you needed to put in extra hours, you either went in extra early or stayed until well after dark -- and missed out on family dinners or dropping kids off at school. Today we are untethered. If you have a conference call with Europe in the morning or with India in the evening, nobody cares where you are when you're doing it. When it's time to leave the office and go home to the family, you just go -- and do the call from wherever you are when it's time to dial in.