I learned a very useful fact today when I was reading the SharePoint Best Practices book. I was always led to believe that you had to allow people to have a My Site in order for them to be able to maintain their User Profile. As it turns out, when you enable the 'User Personal Features' in the SSP for a user, but don't allow the creation of personal sites, when you go to 'My Links' in the menu and choose 'Manage Links' you will be able to see a link to your 'Profile' page. When you go there, you can edit your User Profile, Colleagues and Memberships.
A very useful feature for those that don't want to release My Sites into the wild, but do want the benefits that User profiles bring to Search.