How do you comment on the user albums?

Also how do you register for the private forums? It's 1:30 a.m. and I am turning stupid. Well that's the excuse I'm using anyway.
When I go into a user's album, and I click on a photo to view it, a box shows up underneath where I can post a comment.

To register for the private forums, go to your profile, select "join user groups" and you will find a list of user groups to choose from. Looks like they are all moderated now, so your application will have to be approved before you can see the private forums. I have something to do since I can't sleep...members, beware! Muahahahaha