"AddThis is the world's largest content sharing platform. It gives end users a simple and easy way to share content across the social web, and provides publishers with increased web traffic and in-depth analytics."
Jakob Nielsen, Web design consultant and author of numerous articles on Web site usability, has archived the best of his information here. The permanent content includes information about how people read on the Web, the top ten mistakes Web designers and managers make, technical information about bandwidth and browsers, and much more! The "Spotlight" section includes current news, book reviews, and interviews regarding Web site usability.