You could probably set this up for Metacity in Gnome and others, it seems like I have before, but I discovered it with Compiz.
You can shade the windows up and down by using the mouse wheel. Simple maybe but I never knew that before. It’s really fun to do on a laptop with the touchpad. Saves me time too because I’ve accidentally shaded it more than enough and it was a pain to get down.
Awesome! 
works on my Fedora kde system too so it may be Compiz.
Yep you’re right..
I guess I should change it to “Neat Trick in Compiz” because it doesn’t work in Metacity
Oops. Will fix.
You’re right, it doesn’t work in Metacity.
Ooh official Gnome team member
Thanks for confirming that.
And.. I just realized I didn’t change the URL for this post either.. ugh what’s wrong with my mind?
to toggle shading in metacity you have to set it in config editor with /apps/metacity/window_keybindings/toggle_shaded
Ooh thanks very much
I’ve been curious if I could do this in Metacity, because my computer just doesn’t seem to put up with Compiz very well any more. I’m personally not a fan of window shading, but I’ll try it out.
Thanks again.