Mac: Unclutter is a handy little multi-purpose utility that includes a simple clipboard manager, notes app, and file storage area all packed into a single app.
What makes Unclutter useful is the fact it includes some bare bones, simple apps with a clever interface. Simply move your mouse to the top of the screen, scroll down, and Unclutter displays its three different sections (you can customise the gesture if you want). There, you'll have a clipboard packed with everything you've copied recently, a file storage area where you can drag and drop files for a temporary holding bin, and a notepad to store bits of information. It's simple, but surprisingly handy to have these three apps so readily accessible.