Would the COALESCE be this sort of query?:

DECLARE @EmployeeList varchar(100)

SELECT @EmployeeList = COALESCE(@EmployeeList + ', ', '') + CAST(Emp_UniqueID AS varchar(5))

FROM SalesCallsEmployees

WHERE SalCal_UniqueID = 1

SELECT @EmployeeList

In my experience COALESCE can be a bit of a performance hit. Certainly the above on one of my database columns (varchar(255)) with 22,000+ records the above is about 3-4 times slower than the STUFF...XML method.