In looking over the list, it’s so nice to see WorldCat made the cut in the books category! Library tools are often the red-headed step child of web 2.0; but not in this case. In my never-ending attempt to get us to consume less (and to make libraries look a little more cool), whenever I mention a book online anywhere, I always try to link to the WorldCat info page, rather than Amazon, etc. So often, it seems that people automatically jump to buying a book, rather than checking it out from their local library. May my links to WorldCat be a friendly reminder that a more prudent choice is possible.
And for mostly aesthetic reasons, I am loving Visual Complexity. Pretty pretty!