Get the title of the current active Window/Document in Mac OS X

Refering to a previously asked question, I would like to know how to get the title of the current active document.

I tried the script mention in the answers to the question above. This works, but only gives me the name of the application. For example, I am writing this question: When I fire up the script it gives me the name of the application, i.e. "Firefox". This is pretty neat, but does not really help. I would rather like to capture the title of my current active document. See the image.

Firefox title http://img.skitch.com/20090126-nq2egknhjr928d1s74i9xixckf.jpg

I am using Leopard, so no backward compatibility needed. Also I am using Python's Appkit to gain access to the NSWorkspace class, but if you tell me the Objective-C code, I could figure out the translation to Python.

tell application "System Events"
set frontApp to name of first application process whose frontmost is true
end tell
tell application frontApp
if the (count of windows) is not 0 then
    set window_name to name of front window
end if
end tell

Save as script and invoke it with osascript from the shell.