The geekier amongst us and those familiar with Unix should really like this trick. You can have Mac OS X 10.5 display the full directory path in the Finder window title bar by issuing a simple command from the Terminal.

defaults write com.apple.finder _FXShowPosixPathInTitle -bool YES
Then you’ll want to kill the Finder for changes to take effect:
killall Finder

To disable the full path title bars and revert back to the default, simply repeat the command with NO instead of YES as the operator:
defaults write com.apple.finder _FXShowPosixPathInTitle -bool NO
killall Finder

via: OS X Daily