Cruxlux is bookmarklet you can drag to your browser, or a widget you can put on your blog or website. It’s designed to help you, or visitors to your site, locate similar content on the web. It supposedly analyzes what’s on the site, and then shows you new sites without actually having to leave the page. I’ve embedded the widget in this blog post (it takes five seconds to do so), so you can try it out. Thanks to Read Write Web for the tip.