On the "Family Tree... Last Names Index" option,
- http://www.geni.com/search/surname_index
Please add a radio check option for "All Connected (including collaborators)", "All Those In Tree" and "Direct Descendants Only".
Basically providing the same options that are available in the Tree View, Preferences pane would be ideal.
Right now I see names in my Last Names Index who are collaborators but who really aren't closely related to me which makes the list much less useful than it could be.