Zemanta is a content suggestion engine for your blog, and suggests relevant links, pictures, related content and tags using an internally developed semantic analysis engine. It really is simple to use.
Download the plugin from Zemanta, and start writing a blogpost, and after typing 300 characters, the plugin will give you a suggestion list of Pictures you could use, as well as links relevant to your post. Really simple to use, and works like a bomb.
Download the plugin now, and give it a try. Its Amazing :)