Feel free to add this blinkie to your signature:

I'm not sure if it's different for PC users, but here's what I do:

Right-click (Control-click on a Mac) the image and copy the URL address.
Go to User CP at the top of the DD Forum screen.
Choose "Edit Signature"
Position the cursor where you want the blinkie to appear, click the yellow mountain icon (insert image) and Cmd/Ctrl-V to "paste" the URL of the image.

Feel free to ask for help, as I'm sure there are 52 variations on how to do this. If you have your own photobucket (or similar) account, you might want to save the blinkie in your own account.