http://blogs.msdn.com/echarran/archive/2007/12/18/how-to-move-my-sites-to-a-new-content-database-and-web-application.aspxA great article below on how to move My Sites from an existing content database to a new web application in SharePoint 2007.  Many customers will find this link valuable because having done a database upgrade and not taken the painstaking steps toen-USCommunityServer 2.1 SP1 (Build: 61025.2)