I've been working on a binary format for RDF and SPARQL result sets:
http://afs.github.io/rdf-thrift/
This is now ready to go if everyone is OK with that.
I'm flagging this up for passive consensus because it adds a new
dependency (for Apache Thrift).
And of course any questions or comments.
Summary, as an RDF syntax:
+ x3 faster to parse than N-triples
+ same size as N-triples, and same compression effects with gzip (8-10
compression).
+ Not much additional work to add because Thrift does most of the work.
Andy