I've recently acquired a second screen for my laptop. The external one is, of course, way bigger than the integrated one.

• So I've been wondering, how do you guys set up your Ubuntu for two monitors? The thing is, I'm quite often on the move without my second screen, so I can't really put panels to the second one, as those would be cramped into the first one, once I unplug the second one, right? Also, same goes for windows I arranged and resized on the big screen.
• Another point would be the wallpaper. At the moment, I'm using a wallpaper that's 1920×1980 (I use 1920×1080 and 1440×900 in a vertical alignment) and set the display mode to "stretch", so it covers both desktops. Any easier methods? Don't want to doctor around my wallpapers with gimp all the time.
• As to window window management, I'm currently using compiz and docky. Docky is placed on the top side of the bottom (laptop) monitor so it stays where it was even when the top monitor isn't plugged in.
• what about window placement? My current setup involves using Google Chrome on the top monitor, taking up half of my screen width and being used for regular browsing. Next to it is another Google Chrome window, with the usual "app tabs" of GMail, Facebook, Google Reader and Twitter. Auxilliary stuff goes to the bottom monitor.

So, how are you guys using your dual monitor setup? Any awesome programs I'm missing out on? Maybe one that activates different "configurations" (wallpaper, panels, etc), depending on how many screens there are?