Over at Lambda the Ultimate, Mark Evans points to amk's slides, titling the post " RDF Elevator Pitch". He also mentions suggests "RDF+ReiserFS looks like a match made in heaven". (Hmm, I was wondering about that recently myself).
Problem with an Elevator Pitch for RDF is that it's so wide and deep, the multi-facet elephant thing. Need to be in the lift of a very tall building.
Here's my one-storey offering for today:
RDF provides a relational data model of the Web