One thing I initially hated about HN but have quickly grown to like: usernames are displayed in tiny, faint text. There are no avatar images, signatures, or other visual identifiers. This has a similar, though limited, effect -- it puts the focus on the content, not on the user. (My wife regularly reads my comments without realizing I'm the author; this would not happen on a board with avatars.) Yet it also allows users to build a reputation over time, encouraging us to consistently produce quality content.