Tricks for Mozilla and Mozilla-based browsers (Firefox, Galeon, Nautilus).
Type "about:config" as a URL.
A magic internal webpage will show the browser's settings.
The settings can be edited by right-clicking on them.
These are the same settings that are defined by prefs.js.
Those darn annoying animated GIF images can be disabled by changing this setting:
image.animation_mode, none
To suppress the annoying Default Plugin dialog for downloading Shockwave/Flash plugin crap, remove libnullplugin.so (one of each for Netscape and Mozilla):
/usr/lib/netscape/plugins/libnullplugin.so /usr/lib/mozilla/plugins/libnullplugin.so /opt/firefox/plugins/libnullplugin.so