I would like to create a SQL Server 2005 user account but limit that user to only allow them to have two concurrent connections to the database at once. Is there any way to do this through SQL Server configuration?
You could try Login Triggers: http://technet.microsoft.com/en-us/library/bb326598.aspx
TechNet suggests that:
Their first code example limits a user to 3 connections (Quoting TechNet):