http://www.w3.org/DesignIssues/Semantic: a Web in which machine reasoning will be ubiquitous and devastatingly powerful
http://www.sciam.com/2001/0501issue/0501berners-lee.html
http://infomesh.net/2001/swintro/: The Semantic Web is a mesh of information linked up in such a way as to be easily processable by machines, on a global scale. You can think of it as being an efficient way of representing data on the World Wide Web, or as a globally linked database.
http://logicerror.com/semanticWeb-long by Aaron Swartz
tutorial using N3.
What are some attractive (to me) applications of the Semantic Web?
Reputation Management aggregated across lots of sources (Comments by and about a certain person or organization - Annotation Systems)
- event calendar tracker: agent that watches for alerts you to coming (local) events that may be of interest based (low-tech) on keyword matches
Danny Ayers thinks the Rss Aggregator space makes sense to explore.