The UnGallery plugin is now available to import directories of pictures as a browsable WordPress gallery.
You point UnGallery at a directory hierarchy of photos, even thousands of them, and they are immediately displayed and browsable in your WordPress blog. Any edits you make to the pictures or the organization of your directories are automatically current, on the next browser refresh.
If you've ever had to reorganize where your photos are stored, remove a few or edit the red-eye of a dozen, you know how inconvenient it is to return to the gallery management UI to update everything. With UnGallery, all add/remove/edit changes you make to your pictures are automatically rolled into the gallery view, in WordPress.
Plugin home page here.
WordPress.org download here.
An example installation available here.