Wow, is this possible?  I guess so.  if you have any code or tips i would appreciate it.  I am using the dnn master syncing software to populate dnn with some of the data from the external db user profile but I am in the middle of several things now and it is not clean and matched up correctly at this point.  

you can email me at my firstandlastname @gmail.com if you would like. 

Did the iWeb Module help you with this.  I do not know any other way at the user data.  which is kind of blowing my mind.

thanks for sharing your solution!

The "DNN user system"  well if I can put this in my ruff words as I see it now. 

The SSO module is free and opensouce.  The source code contains inline documentation that should be helpful to developer.

Lesson learned when migrating to DNN:  The intranet contents include static and dynamics.  My team took the phase approach to migrate the content - static first and then the dynamic.  The challenge to this approach was to allow users to access to the new systems using existing accounts.  The SSO module helped to streamline the account administration part since we have thousands of users.

About IWEB:  The current release of SSO module does not use IWEB.  I was looking at IWEB/web service as a solution to make DNN database as the master SSO database.  In our environment, the old intranet database is still the master SSO database.  Once we are done with the migration, the DNN database will be the master SSO.  Non-dnn applications - desktop or legacy apps - can make web service call to IWEB to support SSO.

Good luck on your project.