Great podcast exploring what could become a very important tool for building the semantic web:
"While the web is primarily for human consumption, more sites are including machine readable data. However, this information is usually included separately. As the RFDa Primer states, RFDa provides a set of XHTML attributes to augment visual data with machine-readable hints. RDFa helps bloggers and website authors make their web pages smarter by adding computer-readable information to a site. Elias Torres and Ben Adida talk about it, including its history and what problems RFDa is attempting to solve.
"Torres and Adida also discuss the technical details of RDFa and give a detailed technical description of how RDFa works. They review the mechanics of RDFa and give examples of its usage."