It hasn't been too long since I exclusively started using mac at home and work so I'm still catching on to some of the great little things Apple has thrown in here.
This morning's enlightenment was around capturing screen shots, both full and partial, on my mac. I was reading a blogpost about apps to replace the Snapper add-on I used to use and the author dropped a subtle hint about shift+command+control+4.
With a little search engine power, I found a useful page from apple, http://www.apple.com/pro/tips/secretcapture.html.
Command+Shift+3 = Screenshot Saved To Desktop
Command+Shift+4 = CrossHairs For Snapping To Desktop
Shift+Command+Shift+3 ( or 4) = .... To Clipboard For Pasting to Photoshop/eMails etc...