A nice intro paper on SW, including RDFa

Worth bookmarking:

http://www.ibm.com/developerworks/xml/library/x-plansemantic/index.html?ca=drs-

[[[
With Microformats, semantic value is added to existing HTML content by 
using consistent patterns of standard HTML elements and attributes. 
Microformats exist for narrow but common items of data such as contact 
information and calendar items. The W3C equivalent is RDFa, RDF data 
embedded in XHTML. The implementation is slightly more complex than 
Microformats but it is far more generic—anything which you can express 
in RDF, you can add to XHTML documents using RDFa. Through this 
technique the Semantic Web can be bootstrapped by existing Web content.
]]]

Ivan

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf