Saw this SQL Login Killer Script on SQL Server Central (yes I know it's old, but it's still good) ...

Handy when you need to kill everyone off in order to perform a restore. I even use it on my dev workstation, since IIS, ColdFusion, & a million other things like to hang on.

Although, I wonder if SQL Server 2005 has an easier way to boot everyone off. Hmm.