I have one and I am finding it both addictive and intrusive. I can remember getting my first work email account back in the mid-90's and it was going to be amazing how much more free time you will have with such a nifty application. Our desktops were all individually hooked up to the Internet via our own dial up modems and there would be a cacophany of sound as the modems would wirr and beep every morning. The speed was amazing as it took "just minutes" to load a website.
We had a 12 year old boy - a nephew of an employee - come in and design a website for my work and it took him just 4 hours and he got $200! (We werent terribly concerned that the website looked like it had been designed by a 12 year old boy, that wasnt the point!)
The new age of "greater efficiency at the office equating to greater hours of relaxation time" had arrived.
Now, fast forward 10-12 years, this morning my neighbour in the next cube is tired because he has been dealing with our partners in Spain all weekend via his Blackberry and laptop, my boss is in a tizz because some deal has gone awry over the weekend and he has 100's of emails in his system, I myself spent the greater part of my train trip in dealing with an issue from our Adelaide office that cropped up over the weekend and we all have these little black devices within arm reach of us 24x7 to deal with any crisis that may arise.
And thats the difference... with email, the definition of a "crisis" has changed... basically it is now expected that you deal with ANYTHING that comes onto your email - either via the work PC or the BlackBerry - with immediate expediancy. No longer do we "deal with it on Monday", but now it is the norm that things are dealt with before anything else - even if thats a family matter.
Sad, but true, we are now working longer than ever before....