1. the image has to be hosted somewhere the web (e.g., can't be on your computer hardrive).
2. find the address for the image itself (e.g., it should not be a ".html" webpage address but a ".jpg" or ".gif" address). note, websites with frames will often give you a false address for the fame and not the image. you want just the image (try opening the image in a new window).
3. then create the following post in speedzilla using the image's address (but remove all spaces - spaces were included so the text, and not the image, would appear for you):

[ i m g ] h t t p : / / w w w . g e o c i t i e s . c o m / e d w y u n / g p s 4 . j p g [ / i m g ]

Without the spaces, this will give you the image of the red FE above in the thread.

HTH