Web: a while back, I posted some musings about a web service to help authenticate users as members of a private group, similarly to how TypeKey authenticates users in general.
Well, Flickr have just posted this draft authentication API which does this very nicely — it now allows third-party web apps to authenticate against Flickr, TypeKey-style, and perform a limited subset of actions on the user’s behalf.
This means that using Flickr as a group authentication web service is now doable, as far as I can see…