From the webpage:
Welcome to StatLib, a system for distributing statistical software, datasets, and information by electronic mail, FTP and WWW. StatLib started out as an e-mail service and some of the organization still reflects that heritage. We hope that this document will give you sufficient guidance to navigate through the archives. For your convenience there are several sites around the world which serve as full or partial mirrors to StatLib.
An amazing source of software and data. Including sets of webpages for clustering analysis, etc.
Was mentioned in the first R-Podcast episode.