by Carson Reynolds

One thing that drives me nuts about Firefox on OS X is the way it forces downloads to be saved on the desktop. I searched around for solutions and found this thread on metafilter. Unsatisified, I decided to code up my own solution. Please download the OS X droplet, called OpenDelete and give it a try. I also have posted the GPLed source code for those who want to tinker or improve. Below is the readme, which gives more details:

What is OpenDelete?
OpenDelete opens files in their default application and then
immediately deletes them. It is an AppleScript droplet which is
designed to be used by FireFox.

Why is OpenDelete useful?
Have you ever used Firefox to open a lot of files and suddenly
realized that your Desktop is completely littered? OpenDelete is a
hack to solve this problem with any file type of your choosing. Tell
Firefox to use OpenDelete instead of your default application and it
will open and delete the file, keeping your desktop clean.

How does OpenDelete work?
OpenDelete wraps the following AppleScript into an OS X application:

on open names
        repeat with filename in names
                tell application "Finder"
                        open filename
                        delay 1
                        delete filename
                end tell
        end repeat
end open

How do I install OpenDelete?
Drag OpenDelete to your Applications folder. Then use it as the
default helper application in Firefox for a filetype you do not want
to save on your dekstop.

Some file types, such as PDF are set by default to open using
Preview. In order to associate them with OpenDelete, install Mimetype

Next give Firefox permission to install this extension and restart
Firefox. Afterwards navigate to the Tools > Mimetypes… menu. Here
you can select application/pdf and edit its associated
application. Tell Firefox to Open it with OpenDelete.

What does OpenDelete require?
OpenDelete was written and tested on OS X 10.4. MimeTypes was written
for Firefox 1.5

How much does OpenDelete cost?
OpenDelete is free software released under the GNU General Public
License. See gpl.txt for more information.