When you drag and drop attachments from Mail.app in Panther, the attachments are saved as read only (see this hint). I wrote an AppleScript to solve this problem.
To use it, simply save the code below in a script, and then attach it as the folder action on the destination folder where you usually drag and drop attachments (in my case, this is the Desktop folder).
on adding folder items to this_folder after receiving these_items
tell application "Finder"
repeat with i from 1 to number of items in these_items
if the owner privileges of item i of these_items is read only then
set owner privileges of item i of these_items to read write
end if
end repeat
end tell
end adding folder items to
From now on, whenever you drag and drop a read-only file to the destination folder, it will be converted to read-write by the owner. Obviously, if you habitually drag and drop a lot of read only items to the Desktop, and you intend to keep them read only, you should not use this script.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031212215917675