AppleScript Output (ASO) is an application which provides a global floating window (thats a window which floats over all applications), to which you can send output from your AppleScripts.

It receives AppleScript commands (it has its own AppleScript dictionary which you can view with your favorite script editor) and displays text in its window. It can display multiple lines of text with a scrolling display, and it can save the text to a file. It can stamp the saved files with the current date and time, if you choose.
It can also play an alert sound, if you want audible feedback when new text is displayed.