Just passing this along - thought it was interesting...
http://www.examiner.com/x-5954-Seattle-Martial-Arts-Examiner~y2009m3d31-When-to-crosstrain-in-Martial-Arts
http://www.examiner.com/x-5954-Seattle-Martial-Arts-Examiner~y2009m3d31-When-to-crosstrain-in-Martial-Arts