[mssql] Get Client IP Address

DECLARE @cHost varchar(25)     --> Declare variable
SELECT @cHost = host_name()    --> store to variable
SELECT @cHost AS host_name     --> show result

Source:
http://www.dbforums.com/archive/index.php/t-1604725.html
http://msdn2.microsoft.com/en-us/library/ms174427.aspx