http://www.viperalley.com/gallery/index.php You'll notice a new category called "Forum Attachments". This is an index to the attachments people have uploaded to my site.
First thing I did was change the uploads directory to the category I created for this. Now all images are uploaded directly into a PhotoPost directory.
Next thing I did was write an import script to import all my attachments (ones that PhotoPost can read - images and multimedia) into my PhotoPost database, creating medium and thumbnail sizes and setting the title to the subject of the post. I have about 4,000 images to process.
You can delete images from the gallery and they will not effect your original post. I modified Threads to not remove images when a post is deleted so as to preserve the images.
I've also modified the showphoto.tmpl to show the UBBCODE for an image and also provide a link to whatever thread the post came from.
As always, looking for comments or feedback.