A new feature to upload multiple images all at the same time has (finally) been added to SummitPost. The tool can be accessed here:
https://www.summitpost.org/bulk_image_uploader.php
The main upload image process was altered too, as this feature was added, to check the EXIF data and rotate the image if it is incorrectly rotated and also get latitude and longitude coordinates from the image and use them if none are specified in the form.
If you have a page created and would like to add multiple images to it at the same time, look for the "Add Multiple Images" link in the left sidebar of the page. All images uploaded in that session will automatically inherit the latitude and longitude of the page, along with being attached to that page.
This bulk image uploading tool has been tested but not exceptionally thoroughly. Please post any bugs related to this tool here. Thanks!