Using keyboard shortcuts while editing your photos can save you loads of time, and cheat sheets are a good way of learning them. If you’re too lazy to print one out or save one as an image on your computer, there’s an app called CheatSheet that’s designed just for you. It’s a free Mac App that runs silently in the background. Whenever you hold down the Command (?) key for ~3 seconds, it brings up a complete list of command shortcuts offered by whatever app you’re currently using. We’ve tested it and it works fine for Photoshop, though we wished that it also included non-Command key shortcuts as well.
CheatSheet (via OS X Daily via Lifehacker)