Dual screen in Ubuntu Unity/compiz

Besides what is obvious from configuring Displays, there is a useful shortcut that I did not find anywhere documented:

Start+P

It cycles through different display configurations (for the built-in LVDS notebook screen and for the external display). Unity tends to forget the settings in some cases (suspending the machine, disconnecting from the display) and this is where the shortcut becomes useful.

All windows end up on the first virtual desktop though. I did not find a solution for that. One can set up rules in compiz (with the ccsm utility) so that specific windows appear on specific virtual desktops, appear maximized, etc, then noone can move them from that position.