Dear Researchers, 

I am looking for a way to be able to ask a physics/nanotechnology
related question in a private/confidential way.

How should we proceed ?

Thanks

You hire a consultant and have him sign a non-disclosure agreement

SEARCH WORDS :freelance consulting

e.g. 
http://www.elance.com/

more specific
SEARCH WORDS: consulting technical science
e.g.
http://users.galesburg.net/~atkins/overview.html

SEARCH TERMS:  NONDISCLOSURE FORM

e.g. 
http://my.execpc.com/~mhallign/form1.html

You may also find these past GA answers on nanotech useful:

http://answers.google.com/answers/threadview?id=500730

http://answers.google.com/answers/threadview?id=108507

Your original question is probably not as big a challenge as your
second question is. Everything here is viewable by the public.

tutuzdad-ga

If your queries need to be confidential, then you probably ought to
consult an expert, such as a professor, via more secure means, such as
by telephone or mail. Do some Googling for nanotechnology to see who's
working on it.