Yes, you are right that you need to get a user to identify themselves on a service. Auth is definitely the most common methods, but for many services you can s

Yes, you are right that you need to get a user to identify themselves on a service. Auth is definitely the most common methods, but for many services you can simply as for a username (ex. twitter or instagram). We definitely recognize that there's a lot of permutations in terms of how to make this as usable as possible and we'll continue to add more support for those other options. We started here so that it would be possible for apps with existing authentications to easily work with the service but also be able to expand to other services as well as uploads - as they felt appropriate for their own users. It's definitely not a solution for everyone. Also, we actually provide auth services for Facebook, Flickr, Picasa, Instagram, and more. If you take a look at the mobile components, you'll see that we actually are handling the authentication there to capture the appropriate credentials and map it to the avatar. We'll be brining these to the web side very soon - we already do it with our other product, SlideChute.com. Thanks for the input... and I definitely think I understand your concerns.