SSMS Plus is a lightweight addin for SQL Server Management Studio that automatically names query windows based on their contents, removing the problem of having to search through a proliferation of open untitled query windows to find what you are looking for. It also provides a useful auto-save function (to My Documents \ SQL Server Management Studio \ Queries).
Maybe it's just me, but this literally doubles my productivity within SSMS.
e.g. Before :
After :
Whilst I'm here, please let me plug links to BlueSSIS (
http://bluessis.com) - our comprehensive SQL Server Integration Services component library, and BlueIntegrator (
http://blueintegrator.com) - our free BizTalk competitor.