Here is a link to Steve White's web site. He teaches classes now I guess. I didn't know that. He sells videotapes, so if you are honestly interested in seeing if clicker training works, I'd suggest buying one.
http://www.puppyworks.com/events/white/sw0102nc.html
This is a little of his background:
As a police officer, Steve was trainer for one the largest police K-9 units in Washington State. With K-9 assignments occupying much of his 25 years in law enforcement, he handled and trained patrol and narcotics dogs for military, county, and city law enforcement agencies. Accredited as a Master Trainer in 1993 by the Washington State Police Canine Association. Steve is an instructor for the K9 Academy for Law Enforcement, and has instructed at police K-9 seminars across the U.S.. He has been recognized as an expert witness by Washington courts in police K-9 and dog behavior matters.
Also, here is an article on using the clicker to teach a schutzhund retrieve:
http://www.geocities.com/jetflair/retrievearticle.html
And, for your Schutzhund enthusiasts out there who assume motivational training for competition could never work, there's a book on it:
Schutzhund Obedience: Training in Drive by Dildei and Booth. The original book on motivational Schutzhund training, it is an excellent guide to one type of motivational training and well worth reading.