If you're on a Mac and you're happy with the clipboard, read no further. If, on the other hand, you long for a clipboard that's more sophisticated you might want to check out CopyPaste Pro from Plum Amazing LLC. CopyPaste Pro is, as the company, says like Time Machine for your clipboard. But it's also so much more.
There are three on-screen components of CopyPaste Pro: the CopyPaste Pro menu available from the OS X menu bar and two floating icons (which can be located anywhere convenient on your screen), one with an "H" for the Clip History and another labelled "A" for the Clip Archive. Clicking on the icons displays the actual items in the History and Archive respectively.
CopyPaste Pro provides multiple clipboards so that each copy (Command+c) is saved. You can, as usual, paste the current (i.e. last) copied clip with Command+v or you can type Command+v,v (that's holding down the command key and pressing v twice without releasing the command key) to display the Clip History browser:
Pressing v for a third time will cycle through the available clips and when the keys are released the selected clip will be pasted. You can also drag a clip from the browser directly to the target document.
If you press Control+v,v then press c, the Clip Archive browser is displayed. In this view, to paste an item, you have to type the item's number (still keeping the Command key held down) or, as with the Clip History, you can drag and drop clips into a document.
Clicking on the floating icons opens the Clip History and Clip Archive Palettes to manage clips. You can directly drag clips between the pallets and to and from documents. You can lock clips to prevent overwriting as well as reorder and delete clips.
The tool menu options in the palettes provide what are termed Local Tools. These act on stored clips while the Global Tools in the menu in the OS X menu bar operate on the currently selected text in documents.
Both sets of tools include URL shortening, calculation (i.e. selecting "3^3" and selecting the calculate tool from the menu replaces the text with "3^3 = 27"), and text manipulation such as Clean and Unwrap Text (which removes all HTML tags, interprets HTML special characters, etc.) and Remove Styles (gets rid of style information in text). Two particularly useful tools are Extract and Sort Email Addresses and Extract and Sort Internet Addresses (URLs).
CopyPaste Pro might sound slightly complicated but, in practice, you get used to the new keystrokes very quickly and the improvement in speed when you have repetitive edits to do is amazing. Priced at a reasonable $30 this is definitively a power tool for the power user and gets a Gearhead rating of 5 out of 5.