Contributed By: Cliff Hobbs [MVP SMS]
You can download SQL 2005 SP2 at:

http://www.microsoft.com/downloads/details.aspx?FamilyId=d07219b2-1e23-49c8-8f0c-63fa18f26d3a&DisplayLang=en

It's worth checking out the "SQL Server 2005 Service Pack 2" page which includes links:

• To download SQL 2005 SP2
• To download SQL Server 2005 Express Edition SP2
• Details of new features and functionality
• To view Readme files for SQL Server 2005 SP2
• To download the updated SQL Server 2005 Books Online which has been updated as of February 2007
• To download SQL Server 2005 Feature Pack
• To download updated SQL Server 2005 samples and sample databases
• To download SQL Server 2005 Reporting Services Add-in for Microsoft SharePoint Technologies
• To download SQL Server 2005 Data Mining Add-ins for Microsoft Office 2007

IMPORTANT: If you downloaded SQL Server 2005 SP2 before March 5, 2007 please read Microsoft Knowledge Base article 933508 "Microsoft SQL Server 2005 Service Pack 2 issue: Cleanup tasks run at different intervals than intended" in relation to an important issue with SP2.
 

To see other SMS 2003 Design and Planning related FAQs click here.