Can I change the application icon of an Automator script?
After the script has been created do the following :


Find the source app with the icon you want
Get Info of the source app (cmd-i)
Click on the icon inside the source app's info window
(Not the one in the big Preview section at the bottom, if you have one of those; the little one in the top-left corner.)
Copy it (cmd-c)
Get Info of the automator script (i.e., the destination app) (cmd-i)
Click on the icon inside the destination app's info window
Paste the icon from the clipboard (cmd-v)


This method works for every files in Mac OS X.