In the quest for sql intellisense for the SQL Server 2005 Management Studio I came across SQL Assist for SSMS 2005 from company Round Polygons. SQLAssist can be download it here.
SQL assist works great. Its lighter weight compare to the RedGate tools.
I think its definitely worth the $50 bucks. I initially downloaded the beta version 22.214.171.124, however, this did not work for Windows Vista Business. After installing version 126.96.36.199 I was in business.
Make sure you have SQL Server 2005 Management Studio (Standard or Enterprise) version since this tool will not work with SQL Server 2005 Management Studio Express.