Its probably old news, but to me it is new, so whatever. Anyways, firefox now has themes that arent dependant on the addon that kinda sucks and only works with certain sites. POW! here is the link. Apply one and tell us what it is?

Mine is an animated one of the (iirc) tree spirits from Princess Mononoke...because I have a girlfriend and dont have to worry about a potential person seeing it and losing interest because I am 26 and know what Princess Mononoke is, and have my internet themed in it.