SQL Server - Execute Stored Procedure with Output Parameter?

http://stackoverflow.com/questions/1589466/sql-server-execute-stored-procedure-with-output-parameter
http://msdn.microsoft.com/en-us/library/ms378108(v=sql.90).aspx
http://sqlserverpedia.com/wiki/Stored_Procedures_-_Output_Parameters_%26_Return_Values
http://www.infopathdev.com/blogs/jimmy/archive/2009/08/01/executing-a-stored-procedure-with-output-parameters.aspx