Thru my siggy. just put it in image codes.
copy the link to the image or animated GIF. when you edit your siggy click on the "insert Image" button than paste your image link into the box that comes up and you should see it in your message like below. (just without the 'Spaces' between the code and the link at each end.)
[IMG]
http://www.e-jokes.net/funnypics/100funnyics/66.gif [/IMG]