yes and no. it's a tremendous amount of work to organize information and build associations between what you ask and what you get, although it certainly has a lot of gaps. it's also a neat way to look at how to combine information.

that said it's within grasp of many of us: natural language interfaces (NLI) and SPARQL databases and endpoints. have a look at this semanticweb q&a:

http://answers.semanticweb.com/questions/12747/natural-langu...

some good links in there. basically find your SPARQL endpoints, have a list of synonyms mapped between your inputs (which you parse with NLP tools like weka or the stanford parser, or even python's nltk) and map your query to your ontologie(s) from your endpoints. then try successive answers.

a good, simple interface to play around with that is quepy:

http://quepy.machinalis.com/

a few others exist.

hope that helps. despite challenges in the adoption rates of the semantic web, i think it's the future of information retrieval because it makes sense for us as users and truly organizes information.