I had heard a lot about Folder Actions, but after searching a lot of the script archives, I couldn't find anything really useful. I thought a good use for Folder Actions would be to decrease Desktop clutter, so I wrote this script to maneuver any image files (based on the extension) into an "unfiled" folder in the ~/Pictures directory.
All that you have to do is copy and paste the following text into ScriptEditor, save it as a .scpt file, then apply a folder action to your downloads directory, and voila!
on adding folder items to this_folder after receiving added_items
tell application "Finder"
  repeat with aFile in added_items
  if the name of aFile contains {".jpg"} ¬
  or the name of aFile contains {".gif"} ¬
  or the name of aFile contains {".png"} ¬
  or the name of aFile contains {".pict"} ¬
  or the name of aFile contains {".tiff"} ¬
  or the name of aFile contains {".gif"} ¬
  or the name of aFile contains {".psd"} ¬
  or the name of aFile contains {".bmp"} then
 tell application "Finder"
 try
   move aFile to folder "Mac_name:Users:User_name:Pictures:unfiled:"
    on error err
     display dialog err
  end try
 end tell
 display dialog ¬
"Image files have been moved to the Unfiled folder in your Pictures folder."
 end if
end repeat
end tell
end adding folder items to
Hope you enjoy!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031026201131160