Not sure if this has been addressed or not. However, I like the comment request system. Giving and recieving is always nice but how about the ability to narrow the pictures you get requests on to a certain category.

I, for example, am into CGI so I like to comment on fractals, abstract, computer gen, etc etc and maybe I dont really like pictures of cars to much. I will comment on a pic of a car if it askes me, yes but lets be honest here. Is it going to be a real, sincere, and useful comment? Or an "oh thats nice, lets find something I really enjoy," comment?

Maybe I like to see and comment on all pictures and I can select all categories.

This just comes to mind because I get comment requests for a lot of different types of images. maybe i know nothing about photographing birds or you know nothing about CGI so we both loose besides the fact of that is a nice pic I will say so or eww thats ugly I will just not say anything.