Check out this entry from Jonathan Wells about the MSDN Smart Client Developer Center

This is the link http://blogs.msdn.com/onoj/archive/2004/12/03/274799.aspx

From the site 'The goal of the site is to help you understand smart clients, what they are, when they are most appropriate, and most importantly, the best and most efficient way to construct them.'

This is a great resource for anyone doing Smart Client development.