"A good link building toolbox is invaluable. Some tools provide extra information or insights, while others  point you to possible new link targets. Using a combination of various tools can without a doubt lead to analysis paralysis, but the right set of tools (and no more!) can put you in the right link building direction. In this post, I’m not going to name all link building tools, but simply the ones that I use." - AJ Kohn from Bookmarklet