For most people, I would bet that sending over email is the easiest thing. Create an address specifically for photos and write a script to download the attachme

For most people, I would bet that sending over email is the easiest thing. Create an address specifically for photos and write a script to download the attachments. You might run into issues with attachment sizes of course. But hopefully most people only have 5-10 photos they want to share. For those who want to give you a whole roll of shots, they might just be the edge case where they can just upload to their a shared GDrive or Dropbox.