At first I thought this might be very gimmicky, like many of the OS X window manager tweaks that are out there in the wild. This one I however found very useful. I'll state up front that if you don't often use quicklook, then feel free to ignore the rest of this article.
So what does X-ray mode do for Quick Look? Instead of just seeing the regular folder icon in Quick Look, the folder icon will be semi-transparent, with previews of the folder's contents visible in the Quick Look window. What'...