Great article on how to modify the "out of the box" MySites across the organisation using Master pages, custom server controls and features.
http://blogs.msdn.com/sharepoint/archive/2007/03/22/customizing-moss-2007-my-sites-within-the-enterprise.aspx
About hangseesing
I'm a Software Engineer by trade, the last few years I've been involved in a large public sector organisation as a Solutions Architect. I specialise in Sharepoint and related technologies.