Yah, Lappy's idea doesn't work out too well, it has a few stuff messes up. The best is a combination of Lappy's method (php.ini) and the .htaccess method. Then it works for everything. However, all extensions have to entered manually, and someone can just save something with a different extension, and add a MIME type, and use that to go around the ads. Mod_layout works best.
I tried installing mod_layout a while ago, but something seriously messed up during the compile process. Ermm, any Linux and/or Apache experts here?