Lee Bryant at Headshift has a great entry on social stuff that isn't blogs:

...Looking beyond blog and wikis, many other types of tools are adopting socially connected characteristics, such as photo sharing, social bookmarking, notetaking and many other types of applications. We will need better aggregation and concept matching tools in order to pull together an increasing amount of online interaction that is becoming spread across too many places right now. Ton touches upon this in his response to Stuart Henshall's announcement that he is moving away from 'traditional blogging', Marc Canter has been talking about digital lifestyle aggregators for some time. Seb Paquet recently wrote about commentlogging, which involves using del.icio.us to create a personal trail of comments and discussions that a user takes part in, and del.icio.us backlinks to see who has bookmarked a given page. The meticulous Phil Gyford also scripted a tool recently to pull together his varied output into a composite RSS feed to make it easier to follow his tracks. Finally, of course, Technorati is doing an excellent job of tying together weblog conversations and themes, and we can expect a lot more from the sleeping giant in this space: Google.

Several related techniques that rose to prominence during 2004 will become focal points for technical development during 2005 to support the requirements of more active, more sophisticated communities of people using social software to help them manage their lives and work.

One of these is folksonomies (aka social tagging or ethnoclassification). We have been using this approach for over a year in a social knowledge sharing community and it has produced some very interesting results that we will be reviewing soon to inform future development in this area. It is not without its limitations, and it should not be seen as competing exclusively with traditional metadata structures, but more than any other idea last year this one captured the imagination of those of us who strive to give people more control over the language, relationships and structure of their own information. This technique is a close relation to collaborative filtering - social bookmarking tool del.icio.us is driven by social tagging, whilst Digg is driven by user ratings - and we can probably expect new and exciting combinations of the two approaches in new social software tools.

Another is the pursuit of simplicity, adaptability and tolerance of ambiguity on the client side, whilst applying computing power on the server side to make users' lives a little easier....

...via Designing for a Civil Society