Radar's comment feature allows users to post a public comment on a person's photo, or post a special comment called a whisper that only the owner will see. The owner may click the small X icons next to the comments to delete. The whisper feature is a nice idea, and the execution is dead simple. Allowing comments when viewing a set of photos in list view is very thoughtful and feels right, since these are small-sized cell phone pictures. It may not be necessary to view the full photos at all. The idea here seems more like microblogging the thumbnail sized cell phone snapshots, and micro commenting feels very appropriate.

1. Comments form with comment/whisper buttons below input.
2. Comments form shown adjacent to full photo.
3. Comments form shown expanded below a photo in list view.

http://radar.net