Nice interview with Arika Okrent on her new book “In the Land of Invented Languages” including a good description of the Whorf Hypothesis and an in depth discussion of a variety of invented languages, originally done in 2009.

http://www.onpointradio.org/2009/06/invented-languages

Current comments on the issue:
http://www.onpointradio.org/2010/09/speaking-invented-languages

And as long we are on invented languages, the theme song of all invented languages, SuvwI’pu’ qan tu’lu’be’, by the Klingon rapper, Klenginem.
http://www.youtube.com/watch?v=LBtj4WoC6XA