Hmmmmm........
The picture gallery's purpose is as a public viewing medium, while the forum seems to make more sense (to me anyways) for posting pictures to specific people, anyways.
Granted, not having "Forum Uploads" enabled on your site tends to make that a mite more difficult.
I'll give it some consideration, but truth-be-told, that functionality is handled by enabling forum uploads, part of the reason for the cost of forum uploads, however, is primarily for the extra space associated with having any member of your website capable of uploading whatever they want, whenever they want....that fills up space quickly
