One custom request I haven’t ran across to often is to add a custom search center of the My Sites within SharePoint MOSS.
Typically, when you do a search within My Sites it will default back to whatever search center, if any, you set up for the main site. The one thing to keep in mind is that each My Site is it’s own separate site collection. This means that if you create a new search center subsite then point the search settings to that My Site it will only be for that one My Site. Other My Sites will still be pointed back to the default.

