SQL Server 2005's Integration Services is a pain to get going. Most people agree that SQL Server 2000's Data Transformation Services (DTS) were much easier to work with. So maybe you inherited an existing infrastructure that uses SQL Server 2000 and you want to upgrade it to SQL Server 2005 but you hesitate because of SSIS. Or maybe you have a DTS package that runs perfectly fine, so you keep around a SQL Server 2000 box just for that purpose.
Bridge the gap with the Feature Pack for Microsoft SQL Server 2005 - April 2006. Specifically you want the Microsoft SQL Server 2000 DTS Designer Components. After installing this on a computer with SQL Server Management Studio 2005 you will be able to edit and run DTS packages.