The DARPA Spectrum Challenge was held last week. This is an interesting event encouraging innovation in using spectrum much more efficiently.
This is one of those events where it would have been nice to have been there, and talk to some of the people involved in the various entries.
The technologies being developed have huge potential impact for "unlicensed" (really public licensed) spectrum, both existing and future.
Perhaps the biggest outcome was the further validation that cooperating radios can share spectrum, without any central authority or database. Of course, we already knew that, but this is an extra data point to give regulators courage to make TV white space and other shared spectrum resources available for general use.