except from my ~/.profile . i use this all the time!

.profile

# change directory to the currently open finder window.
cdf () {
        currFolderPath=$( /usr/bin/osascript << EOT
                tell application "Finder"
                        try
                                set currFolder to (folder of the front window as alias)
                        on error
                                set currFolder to (path to desktop folder as alias)
                        end try
                        POSIX path of currFolder
                end tell
EOT
        )
        echo "cd \"$currFolderPath\""
        cd "$currFolderPath"
}