title: What's the best practice or design pattern for user registration?
body: <p>We have a big portal that needs user registration to allow them use its services.  It's already done in .NET and SOL Server 2005. We are in the phase now of discovering all the problems of the current registration system to build a new robust and flexible one that can be extended easily and can be more usable for all services.</p>
  
  <p>What are some best practices and design patterns to rebuild this using good architectural practices?</p>