The new Mac OS is out, and if you can’t decide whether to drop the $29 (hint: you should), Shawn Blanc’s review is the one to read. He’s great at reviewing things like a regular person, and this one’s no exception. One feature he’s excited about, that’s worth $30 to me by itself, is the second-monitor-management:

In Lion, this behavior has been greatly improved:

With the laptop lid closed and the computer asleep: Plug an external display in, wake the computer, and the external display will be the only working display. If you were to then open your laptop lid, the laptop’s screen would turn on and you have two working monitors.

With the laptop lid open and the computer awake: Plug an external display in and you have two working screens. If you were to then close your laptop lid, the laptop’s screen turns off and the external monitor becomes the only working monitor.