ConsoleScripts http://brianswisher.com/consolescripts/

Summary:

This is a library of javascript utilities that can be used on web pages at runtime through a javascript console or bookmark-let. They're meant as tools for development or proof of concept work. Start with a script that provides the core function you're looking for and build on top of it. Properties of a consoleScript:

1. Wrapped in JavaScript closures to protect namespaces.
2. Small, specific, & portable.
3. Don't take the time to degrade for less capable browsers.
4. Pass JSLINT, unless justified otherwise.