I’m not sure about that gallery, but theoretically you could do something like this in a fashion if you used the AWSOM Pixgallery plugin and set a folder to allow anonymous FTP access. Then anyone could upload images to the folder that would be automatically added to and displayed in a gallery that was set to view this folder.
However, I would caution you about allowing anyone to be able to upload images directly to your site. The best solution is to have people simply email you an image which you could then approve and add to a gallery yourself. Yes, it’s more work, but it lowers the possibility of someone uploading a malicious file to your server (like a virus file) and causing your users and your site to get infected.
