Here’s a AS3 debugger that allows you to ‘trace’ out things no matter if the swf is running in a webpage or whatever.
You use the stand alone AIR app to capture the output
http://arthropod.stopp.se/
The use is like so ..
import Debug;
Debug.log(“Hey there”); // traces “Hey there”
Debug.log(“Hey there”,0xFF0000); // traces “Hey there” in red

Thanks Mark Fennell for the link!