Ok, here it goes.
First the image must be hosted somewhere. It could be on your personal space the most ISPs give you, on putfile.com or some external hosting spot.
Then, you reference the URL inside IMG tags. There's an IMG tag buttom below the Subject field when you compose a thread.
Here's an example.
Using this line in a thread automatically shows the image below by putting '
http://www.gameplanpinball.com/sharpshooter1.jpg' inside the IMG tags (without quotes).
