[KimDaBa] from categories to group?

[manouchk]

Hi,

I'd like to know if it's possible to modify a category inder to make it a 
group. For example, I made a category named "Rio de Janeiro" and I would like 
to create a category "Ipanema" and then make "Ipanema" beeing a memeber of 
"Rio de Janeiro". 
I found I could do that moving "Rio de Janeiro" category to "Rio de 
Janeiro-old", create group "Rio de Janeiro" and had select all photos with 
category "Rio de Janeiro-old" and put them the "Rio de Janeiro" group.
Is there something easier?

If I understand well category and group are distinct type of things. It makes 
me think that it could be the same type of thing because one could think of 
an hybrid category-group that could have both "parents" and "children". I'm 
also thinking of a hierarchical and graphical editor of that 
"family-tree"....


Cheers,
Emmanuel