Menu bar app keeps a history of text and graphics you’ve copied, plus has a section for snippets you can create in categories for use when needed. Completely accessible via the keyboard, using a floating palette.
Open source fork of Jumpcut pops up a bezel containing recent items that you’ve copied. You can go through them with arrow keys to find the one you want and paste it. Default hotkey is Shift-Command-V.
Save up multiple snippets of text and paste them at will from the menu bar or from a translucent display invoked by a keyboard shortcut. KoolClip works in a similar manner.
Keeps track of the last 20 (changeable in preferences) items that you copied or cut and allows you to paste them at any time.