Here is a great article on the right way to customize MOSS MySites. Thanks to Jingmei for bringing this to my attention. I got chastised for being too "old school" about customizing the .aspx pages. If any of you are thinking about doing that here is an excerpt:
First, let’s start with how NOT to customize My Sites. As with SPS 2003, some people might think “Hey, I can modify things pretty quickly if I just go to the file system and change the template for My Sites there.” This is absolutely the wrong approach, and it will leave your site in an unsupported state. This means modifying any of the .aspx pages or onet.xml or any of the other out of the box templates files is off limits.