Unguessable URLs for easy sharing
I don't want to make my photos public, but I definitely want to share specific photos or albums by sending a link in an email or in chat. This is a solved problem.
Picasaweb has a "link to this photo" or "link to this album" option on every applicable page. You can share the photo/album regardless of whether it is public or private by pasting the secure URL it generates. Here is an example URL:
They also have the option to reset the secret URL for albums.
Flickr also has this feature, they call it a "Guest Pass".
Google docs has this as well... it is very useful and pretty common.
I'm really looking forward to use this feature, too
What I always had in mind as a user (receiving links from picasa) is, that links to different albums don't remember me.
What I want to have is, that I have one single link to openphoto, and openphoto knows, which albums/photos I'm allowed to see, even when I'm not a registered openphoto user
We are working on this. In fact it's going to replace the groups feature we have now.