The datastore titles used in PhotoPlog need to be changed to allow for different categories, the PhotoPlog variable names need to be changed to avoid collision, the PhotoPlog product and files need to be renamed to allow for a separate install, and there could be other things I'm not thinking of at the moment.
When I installed both Lite 'n Pro on this site, I went for a totally separate instance though it might be possible to make it so the same phrases and templates are used in two cases of a Lite install. What I remember most about making the two separate PhotoPlog installs is that it was sort of a PITA to do.
