Protect Excel 2007 but allow ungrouping
 

I have an Excel 2007 workbook that has subgroups. I want to allow others to
view the document and group or ungroup, but not make changes to the document.
When I use Mark as Final or if I protect the workbook or worksheet, they
cannot change anything and they cannot ungroup. Is there a setting that
allows them to manipulate the document, but not be able to save those changes?

Thanks!
PJ