nice trick, but a better suggestion would be to: 1. either allow ftp access to the website, 2. create a guest photo upload.php script that uploads them to the import directory and the main admin can login and import them to the website. (like i do) 3. or create a login script with a cpanel where "guest" users can do the last step.
multiple users isn't a bad idea for a feature, but I think step 3, would be where the cpanel code would get integrated with plogger's import feature, so it automatically imports it to the gallery rather than admin import.
sounds great, if i knew php code, i'd create it myself and share it.