Quickscript
My latest Safari extension provides a convenient way to save and automatically run arbitrary bits of JavaScript for any web page. (It’s only useful for pages you don’t control.) Quickscript is similar in purpose to the Firefox extension Greasemonkey, but is much simpler and less powerful—for example, it does not support userscripts.org. On the bright side, Quickscript makes it really quick and easy to add a script, and it includes a copy of jQuery so you can easily include it with your scripts.
