When we were developing the Zadu web site theme, I spent a lot of time fiddling with layers in Photoshop.
I consulted with Brian every once in awhile, and we couldn't decide whether a few carefully placed "rhomboids" was best, or a lot of randomly-spaced ones.
On a whim during one of these impromptu critiques at my desk, I swept down my column of layers and turned them all "on" at once.
Brian said "hey... THAT looks pretty cool..."