The option to keep the background picture stable freaks the hell out of me - it always has. It's pretty much gone into disuse because it freaks the hell out of a lot of people :P I know you like Viggo, but perhaps you could make the background plain-colored.

The mouse gestures are an exension to firefox (there are a lot of cool extensions, you should take some time and check them out - extensions are one of firefox's most powerful features). First, go here for mouse gestures:

http://update.mozilla.org/extensions/moreinfo.php?id=12&vid=741

Then go here to check out all the ones availible - they usually have self-explanitory descriptions.