CREATE LOGIN [devtest] WITH PASSWORD=N'NotTheRealPassword' , DEFAULT_DATABASE=[master], CHECK_EXPIRATION=ON, CHECK_POLICY=ON
GO
EXEC master..sp_addsrvrolemember @loginame = N'devtest', @rolename = N'dbcreator'
GO

EXECUTE AS LOGIN='devtest'
select suser_name() ;--Am i DevTest? yes I Am
CREATE DATABASE myTEST;
REVERT; --change back into superman
DROP DATABASE myTEST;
DROP LOGIN devtest;

--the EXECUTE AS must be a user in the database...not a login
CREATE procedure pr_CallBoostedSecurityProcess
  WITH EXECUTE AS  'superman'
AS
BEGIN
'do priviledges stuff
--dbcc freeproccache
CREATE DATABASE MyDatabase
END 

CREATE USER devtest FOR LOGIN=devtest
GRANT EXECUTE ON myProcedure TO devtest

select * from sys.server_triggers