There is no standard way to not log a specific kind of file or URL or request. You might a) not log anything, b) set up another server on another port (apache, or aolserver, or) to serve JUST your gifs, c) ignore the issue, d) take a look at the nsvhr/nsunix patch I have created available from my site -- amongst those patches is a patch the aolserver/nslog module so that if it finds a header that says, "X-NOLOG", it won't log the request. I use that, as well as a filter to set that header, to keep various requess out of my logs.