Memeorandum is cool. If anybody out there wants to build a Memeorandum clone, the easy part has been done: it's Drupal + aggregator 2 (experimental not in CVS but available from ahwayakchih) module. The hard part is the algorithms. Why use Drupal? Because then you get blended RSS feeds out, RSS feeds for every category, tagging, commenting, forums, etc. for "free" without writing a single line of code. This leaves you free to focus on the hard part which is the algorithms to get and analyze news and their associated conversations from Google News, Pubsub, Feedster, Blogdigger, Technorati, etc. And if you write the algorithms as Drupal modules, you can easily create new memeorandum type sites like katrina.memeorandum as Britt suggests. Kudos to Gabe on the coolness of his algorithms and on the coolness of the site in general.
And so memeorandum offers a set of pages, each page highlighting the best contributions from a different community of writers, recognizing new sources as soon as the community does, and in a form conveying ongoing conversations. Consider each page a news section, or vertical, if you will. For now, there are two: First, memeorandum tracks mostly politics plus various current affairs. Second, tech.memeorandum focuses on technology, particularly business news and innovations in computing and the Internet.
These pages are built automatically, through software, ala Google News. Building the software wasn't easy, and there's a lot more to do to perfect it. But I feel the site represents a big step toward the goals described here.