Actually, I've now realized that KDE doesn't pass the right click to any applications. Right clicking the desktop of KDE will get you a menu (I think I set that somewhere a long time ago), but right clicking in Mozilla or in Evolution or in anything else I've tried it with doesn't work.
I'd be pretty shocked if KDE simply didn't have this functionality and GNOME did. Also, shouldn't all of this stuff be done by X and not a desktop environment? I guess the answer is it's not, but I thought I'd put forward the question anyways. I believe the mouse wheel and middle click (i.e. clicking the mouse wheel) work fine (I can't remember for sure and I'm at work now).
-Venkman