[Fallus]

you could use javascript to detect when the user pressed the right mouse button on your page, and do a return false (or is it void (0) ?), or maybe a msgbox or something... don't have the code right now and can't be bothered to figure it out because I really hate sites that do this...
another option is, if this is the image :

<img src="dontstealthisimage.gif" border="0" width="10" height="10">

change it to :

<table border="0" cellspacing="0" cellpadding="0">
<tr>
<td background="dontstealthisimage.gif"><img src="pix.gif" border="0" width="10" height="10"></td>
</tr>
</table>

(pix.gif being a transparant gif of only one pixel, just so the background will show up in netscape...)

but you'll have to do this with every image in the board - so I suggest writing a function for it... if you have a link around the image, just put it around the transparant gif... that should do the trick...

however, in both cases, a simple 'view source' would show up the HTML, with the (relative) url to the image, so the visitors would still be able to get the image if they want to... (but 99% of the surfers on the web really wouldn't know how to do this...)

hope this helps, but I don't understand why you would want to do this?

oh, another thing : the visitors would probably already have the gif on their hard disk, in the cache of the browser (the browser saves the images of a page in a cache to speed up surfing) - so they could just browse their cache and get the images from there...