Tweaking CSS on sites developed by other people seems to be something that comes up at least weekly in web development. Why isn't my footer displaying properly? Why is this div wrapping? Often it's me asking those questions, but every now and then I can solve someone else's problem with a CSS tweak or two. CSS Pivot, which I discovered via a post from Chris Coyier, is a site that lets you share those tweaks with other people.
I thought it looked useful, so I made a bookmarklet to send the current page to CSS Pivot. Drag it to your bookmarks.