We used this to delete users from the site collection in SharePoint 2007. It was gone in 2010, but really just “hidden.”

Simply paste the following URL into your browser and change the site name and you wll get the All People page back.  Useful for deleting users from the site collection.

http://My2010Site/_layouts/people.aspx?MembershipGroupId=0&FilterField1=ContentType&FilterValue1=Person