Don't forget, if you want to change the way Enterprise Manager logs you in (after you've changed your login to a SQL Server only login) you may have to drop your server registration from EM and re-add it, click the Use SQL Server account, and then it will give you the option of prompting you for a password everytime you log into EM.
2 caveats.
1) If you leave EM open after you login and your computer is unlocked, then anyone can work on the box with your permissions.
2) You can only get the prompt if using a SQL Server login, not if using Windows Auth.
Catadmin - MCDBA, MCSA
"If a person is Microsoft Certified, does that mean that Microsoft pays the bills for the funny white jackets that tie in the back???