Even better, If you're using SQL Server 2005 -- no need to detach, just set offline -- I posted script here:

http://mpdsharepoint.blogspot.com/2009/06/why-ask-dba-move-sharepoint-content.html

Great time saver. I have to move mdf files for 198 databases and this is perfect. One thing I added was below Alter command to drop connections prior...