New Ajax social bookmark URL(you can see with what tags one have bookmarked you) and tag search. Says it will be adding more social bookmarking query services almost daily.
B. Krause, R. Jäschke, A. Hotho, and G. Stumme. HT '08: Proceedings of the Nineteenth ACM Conference on Hypertext and Hypermedia, page 157--166. New York, NY, USA, ACM, (2008)
B. Krause, R. Jäschke, A. Hotho, and G. Stumme. HT '08: Proceedings of the Nineteenth ACM Conference on Hypertext and Hypermedia, page 157-166. New York, NY, USA, ACM, (2008)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. The Semantic Web: Research and Applications, 3rd European Semantic Web Conference, ESWC 2006, Budva, Montenegro, volume 4011 of Lecture Notes in Computer Science, page 411-426. Berlin / Heidelberg, Springer, (11-14 June 2006)