The other option is SQL Reporting services which is included in the license of SQL Server 2000. So, if you have a SQL Server 2000 license you can run a matching SQL Reporting Services server. There are no user limitations on it that I know of.
Licensing SQL server Reporting, is NOT required if SQL server reporting is on the same machine as SQL server, then they share the same license and cals.
But as soon as you install SQL server reporting on another server that doesn't have SQL server then you need a license for SQL server reporting and cals.
--Shawn