p2pfoundation has an interesting post about the importance of time as a dimension in social networking technology. My concept of RhNav - RhizomeNavigation includes some of these thoughts...
J. Heer, F. Viégas, and M. Wattenberg. CHI '07: Proceedings of the SIGCHI conference on Human factors in computing systems, page 1029--1038. New York, NY, USA, ACM, (2007)
J. Heer, and D. Boyd. INFOVIS '05: Proceedings of the Proceedings of the 2005 IEEE Symposium on Information Visualization, page 5. Washington, DC, USA, IEEE Computer Society, (2005)
T. Dwyer, S. Hong, D. Koschützki, F. Schreiber, and K. Xu. APVIS '06: Proceedings of the Asia Pacific symposium on Information visualisation, page 189--197. Darlinghurst, Australia, Australia, Australian Computer Society, Inc., (2006)
C. de Souza, S. Quirk, E. Trainer, and D. Redmiles. Proceedings of the 2007 international ACM conference on Supporting group work, page 147--156. New York, NY, USA, ACM, (2007)
P. Heymann, D. Ramage, and H. Garcia-Molina. SIGIR '08: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval, page 531--538. New York, NY, USA, ACM, (2008)
M. Chatti, M. Jarke, T. Indriasari, and M. Specht. Learning in the Synergy of Multiple Disciplines, Proceedings of the EC-TEL 2009, volume 5794 of Lecture Notes in Computer Science, Berlin/Heidelberg, Springer, (October 2009)