I've been looking into RDF
recently, as I'm writing an XML-based bibliography tool (by the way,
if anyone knows of an existing RDF vocabulary for describing citations
in journals, please, please, please mail me and let me know what it is),
and it looks pretty useful for a variety of things, including a
messaging/blogging/browsing thingy I've been vaguely thinking about
for a while now - more when and if I get round to writing it.
Anyway, while scouring the web for resources (there are lots, as long
as what you're interested in is RSS; I'm not), I came across a nice
antidote to
metadata. Handy to bring you down to earth if you're getting
carried away with the whole semantic web thing.