Detect Displays is an applescript that makes it dead-simple to detect any displays connected to your mac that aren't currently detected. Scenario: you have an external display plugged in to your sleeping MacBook with its lid closed. If you wake up that MacBook with an external keyboard or mouse the display will stay asleep even if you lift the lid. Running this script is faster than clicking "Detect Displays" after navigating to System Preferences -> Displays.
Install the script by typing rake install in this directory. This will
compile the AppleScript into a .scpt file and copy it into your
~/Library/Scripts folder.
I run the script with Launchbar.
You could also bind the script to a shortcut key in the system with an application like FastScripts or a Quicksilver trigger.
Inspired by Yehuda Katz's osx-window-sizing repository.