instructions.txt

1) Add the function below into your .bash_profile, .bash_login, or other shell profile file.
2) Then you can hit nt (for new tab) anywhere
   and a new tab will open up in same directory.

All credit for the idea and applescript goes to @jnunemaker - I just tidied it up.
If you can improve it further, let him know -- nunemaker@gmail.com.

terminal_clone_tab.sh

function nt {
  terminal_clone_command="
tell application \"Terminal\"
  tell application \"System Events\" to tell process \"Terminal\" to keystroke \"t\" using command down
  do script with command \"cd `pwd`; clear\" in  selected tab of the front window
end tell
"
  echo "$terminal_clone_command" | osascript &>/dev/null
}