I find myself using it increasingly more often for work, it takes some of the neck strain away, from looking down all the time. It also removes alot of the eye strain from connecting to user workstations which have dual display setups.
Generally I hook my laptop up to a monitor and position the monitor above my laptop, then drag the menu bar to the external monitor to make it the default. That way all my stuff gets moved to the main screen and I kind of just ignore the laptop monitor, but can still use the keyboard and trackpad.
It's also nice because OSX will "remember" that monitor. It positions and moves stuff on the fly to the external when connected, unplug and it moves it back to the laptop screen. I have several monitors I connect to throughout the week.
I do the same thing with my tv at home, I just keep a 15-ft TB-to-hdmi cable tucked behind the tv stand. My wife and I will plug in, it pipes the video and audio to the tv system and we can play whatever shows we want via the MacBooks. She uses it a lot for MTV shows, go figure.