OS X

Quicksilver is a desktop app launcher.

Mac OS X keyboard shortcuts

Finder: Show All Files

To show hidden files in finder:

$ defaults write com.apple.finder AppleShowAllFiles FALSE
$ killall Finder

To hide hidden files in finder:

$ defaults write com.apple.finder AppleShowAllFiles FALSE
$ killall Finder

Note: the finder config file is:

~/Library/Preferences/com.apple.finder.plist