I just presented a talk Bootstrapping the Semantic Web with Redland at XTech describing Redland and how it came about, components etc. There's a paper also which goes into this in more detail but the cute bit is at the last minute I came up with a demonstration, using the slides themselves as the RDF graph. This involves using GRDDL to create an RDF model behind the slides describing the content, and then performing an RDF query over that. Raptor turns the html into RDF for Rasqal, returning the variable binding results. In short:
$ roqet http://www.ilrt.bristol.ac.uk/people/cmdjb/talks/xtech2005/slides.rq
roqet: Querying URI http://www.ilrt.bristol.ac.uk/people/cmdjb/talks/xtech2005/slides.rq
roqet: Query has a variable bindings result
result: [slide=blank genid2, title=string("Bootstrapping the Semantic Web\nwith Redland")]
result: [slide=blank genid3, title=string("Overview")]
result: [slide=blank genid4, title=string("What Is Redland?")]
...
It requires the latest released rasqal 0.9.9 as I'm using the latest SPARQL syntax.