I still remember the days, when I was working into the late nights (rather early mornings) to translate pages of the PHP documentation, and wondered how I can bare the load, without eye sight problems or pains in my body. Well, years of contributing over-hours and practicing bad posture shows its result after all, and after back pains for some time now, since a few weeks ago, I suffer from RSI in my arms as well. Knowing this will happen, I am going out swimming regularly for some time now, and I tried to set up an environment where I can work with better posture.
Welcoming a MacBook Pro to my work environment this last fall, I worked using the laptop on its own for some time, but then realized I'd rather try to integrate it to a better environment using a bigger and better positioned external monitor and an external keyboard. The Apple aluminum keyboard is great, although it's keys are a bit farther away from each other, compared to traditional keyboards I am used to, it is a great experience. But connecting my MacBook to an external display resulted in unexpected problems.
The problem consists of connecting an external monitor to the notebook then using Cmd-TAB as you would and bang, some time later, one of your Cmd-TAB pressing will result in the machine seemingly being frozen. You can move your mouse but no clicking leads to anything being done, and no pressing keys on the external or internal keyboard leads to any action.
The problem persist is MacOS Leopard as well, as noted in the support discussion above, however it seems like a software issue from the symptoms. As users found out and documented there, when you plug in your external monitor, there are some errors shown on the system log, but otherwise everything looks fine. After some usage with Cmd-TAB though, the graphic system hangs. People note that you can ssh to the machine, kill the WindowServer (which kills all your running applications as well), and then log in back again to see everything working again. Not much different to restarting the whole machine.
Another "solution" is to unlearn using Cmd-TAB and instead use exposé or the dock to switch apps. I would not call this a satisfying way either. I tried but failed to unlearn years of app switching.
That said, it looks like I am not going to be able to use an external monitor with my MacBook Pro, so I am on the lookout for laptop stands. The friendly people on #drupal already suggested me some models. In the meantime I also installed AntiRSI as shown in the image above.