Hmm, I like the possibility to turning on/off images in signatures. Personally I'd like to leave it "on" as I'm finding useful information here.

Per user turning on/off images in signatures can be pretty easy, however needs some custom development. When somebody put image to his signature, some special html class should be given to HTML representation of this image. Then anybody can check on/off "Show images in signature" in his account settings, which will modify CSS style 'display' for this html class (that piece of css style can be placed inline to page source)...

Just an idea how not to fed up many forum users...