If you're using TiddlyWiki as your note-taking tool, you ought to give TiddlySnip a try. The idea behind this Firefox extension is simple: it allows you to add the currently viewed Web page or selected text snippet to your TiddlyWiki as a new tiddler. But TiddlySnip adds a few clever twists to this basic idea, which turn the Firefox/TiddlyWiki combo into a powerful and extremely useful tool.