open new tab to current working directory in Mac OS X's Terminal.app

gistfile1.txt

#!/bin/bash
#place this somewhere in Bash's $PATH and chmod +x it....

working_dir=$PWD
/usr/bin/osascript<<END
on run
	tell application "System Events" to tell process "Terminal" to keystroke "t" using command down
	tell application "Terminal" to do script "cd $working_dir" in front window
end run
END