I have successfully gotten family members to use two, count them, two ways to share photos, out of a dozen I suggested.

#1: Dropbox.

#2: http://www.eye.fi/ , which my mother uses to get photos on Facebook despite having no understanding of the file system metaphor.

Personally, I use Dropbox. It's super elegant in terms of the UX for my girlfriend. I take photos, drop them in my Dropbox folder, and send her an email. She makes with the clickyclicky on the magic blue bit. Bam, vacation photos. We both managed to screw things up, frequently, when I was trying to send her photos on Flickr without opening them to the entire Internet. Dropbox makes it a one-click operation for her, and I can manage drag-and-drop on most days.

Why wouldn't an ordinary person want to use it to share photos? Plug in camera, transfer images, right-click and copy the gallery link or hit share. It can't be any easier for the ordinary person.

Dropbox's GUI does need some work for presentation, which is why me and a friend built an app on top of Dropbox precisely for that: views.fm Actually just released a new slideshow feature to present photos!