I would suggest a page where thumbnails ( see Rich's excellent article on such at SkinYourScreen

) could be posted linking to image hosting sites that have heavy security in place.
Although I'd love an independent upload option, this last suggestion might be the easiest to pull off. Something else I'm investigating right now is using an independent form that would permit users to upload a file (or multiple), input a preview image, and a description and have it either committed to a separate MySQL database (separate for security issues) or email it to me directly for approval and submission.
I DID find a modification to my current CMS that will let users create limited CMS accounts from the front-end, but adding new themes/articles still has to occur through the back-end. It's the back-end that I worry about... although it would be a secure system, the admin-side of things for SYS is really messy (as Haxer can vouch). I picked a less popular CMS for security and flexibility: the trade-off was the administrator's interface. Would take some getting used to.
For the sake of simplicity, I'm gonna try the form-based method first. If that works, it'll just be a matter of moderation.
While we're on the topic of change, some other items on the agenda for SYS:
- Graphical design: SYS is a skinning website. It should look like it.
- Reduce footer clutter (the 6 infinite columns at the end).
- Streamline the menu system (hint - AJAX method in the works)
The first point will be something gradually changing, although the next two will be a little more profound when added, hopefully reducing the overwhelming page length.