A universal tool (well, since I use Windows, a Windows tool) to modify the clipboard would be cool.

So, copy text to clipboard, press a hotkey to popup the menu, and it'll offer options depending on the detected text. For example changing the clipboard contents to prettified (if it detects JSON, XML, HTML), or formatting a number back and forth (e.g. working with SSN's out of numerical DB entries when they prefer AAA-GG-SSSS).