This is one of the forever problems with photos and the internet.
It is a bit of a grey area, some people don't mind there photo's been used, where other people will take further action.
As far as I know if the photo does not have a water mark or it is not registered with the owner or on a site, it is fair game, and if the photo is out on the inter webs it is fair game as well, and now Facebook, any photo uploaded onto face book belongs to Facebook.
But it is the right thing for the person who wont's to use the photos to find and ask the owner of the photos if he may indeed use them.
Huzi, I don't think that will happen any time soon, bear this in mind, not every one has the time, money and drive to put hours of work into doing things like this.
Bear this in mind, not every one out there is pro-photography and some pictures are poor quality.
In the time since I have been in the hobby, there was talk about doing a calendar 2 years ago.
Then Tarantulas.co.za brought out there own calendar, this has happened going onto 5years since I first started in the hobby.
The posters are also new in the hobby,
But I wont mind paying R50 for poster with scientific names at a robot though, there is plenty place for people under the sun!
Just depends if you got the fore thought to see the gap in the market and a Entrepreneurs spirit.
But there is a right way and a wrong way to do things.