Here's a real newbie one for ya.
I was just watching John Patton's instructional video on Sprites, and he seems to have a way set up to really quickly change the background colour in his perspective view from black to white (or some grey or other -- the video quality's not that great) and back again.
The only way I know of to do it is to go through the settings/preferences menu. A quick toggle might be handy when a guy's working on particles, or doing playblasts.
Is my tiny brain missing something obvious?