First of all, thanks for offering a fantastic site, that has lots of great info and runs really well! I have a suggestion regarding the galleries. Unless I am mistaken, images are only arranged in the order they were uploaded. This has a few drawbacks because not only are unrelated photos all crammed together (which becomes very disorganised), but it also means that outstanding shots are lost in a sea of photographs.
If possible, could you see if the webteam can arrange it so we can create custom folders and place our photographs in there? Also add a tagging system, so people can not only browse your photographs by album, but by tags such as "portrait" "My Favourites" etc. Custom tags could get messy, but if you expanded the list of tags available when we upload photographs (we have to choose a category like portrait or seascapes, but there isn't a cityscape for example), and allowed us to attach more than one tag to a photographs (for example and image could be both a cityscape and Black & White), then I think it would greatly boost the accessibility of the site, which in turn would lead to more browsing, commenting and hopefully a greater influx of users.
Also another suggestion: Would it be possible to feature a random photographer every day? This might also encourage people to provide feedback to others. Perhaps introduce a system where anyone interested would be able to opt into this (it wouldn't be mandatory), and would only feature active users (for example if you've not connected in 9 months, you probably wouldn't notice and therefore wouldn't benefit from this). Perhaps users can select which photographs they are willing to have featured, so only their best work is presented.
Finally, this has been said before, but I think it's worth mentioning again: the comment system. It's hard for people with large galleries to find which pictures have received comments. It's also far harder to find a picture you've placed a comment on, to see if the photographer has replied to your comment. Perhaps tie the comments into a site messaging service, so every your picture receives a comment, or someone comments on a picture that you have commented on, a message is sent to your inbox and/or email.
Beyond convenience I really think these idea can expand the social aspect of the site. When people know they can interact with each other, see comments and check back on them facebook-style, I imagine they will be more inclined to do so. And of course, more feedback means more input to consider when taking future photographs. Improving our shots is definitely something we all strive for and why you guys work so hard every month to provide us with your excellent articles and stories