Lan Chan asked about commenting on the Insideadog web site and I checked it out. Firstly, yes, you do have to register, then log in - I assume it stops spam comments, so fair enough.
I was confused about the process of commenting, so I asked Adele Walsh, who said you need to click on the title of the post you want to comment on. Once you've done that, a comment box opens underneath. Do go check it out and feel free to comment. That might encourage others to do so; Adele says most IAD readers lurk rather than comment.