The SQL Server Health & History tool, also known as SQLH2, has been posted on CodePlex. You can find the project home page here. SQLH2 is the precursor to the Data Collector feature added in SQL2K8.
But data gather in SQL 2008 will not gather data for SQL2005 or SQL 2000. So what over all good is it but for SQL 2008
David - I'm not sure I understand what you're saying SQLH2 works for SQL2K and SQL2K5.