Painting & Drawing from Copy-right Free Photos

About a month ago I found an artist's website through a British artist I admire.  The site is called Paint My Photo = PMP.  Artists and students gather there to show their art and to get copy-right free photos to work from.  It is a free site although I recommend offering them a donation for upkeep of the site,
I have recommended it to all my students because I am tired of worrying about their art sources.  This site may also encourage them to take photographs and develop them into art.
A heads up - there is a new photography group who are sharing their work but you have to ask the photographers if you can use these pieces for art.  It is the only part that you should be careful and respectful of copy-right.
Here a few of my efforts so far.

8x12 Beach - pencil

8x10 3 China Doves - oil on canvas board

24x36 Snow Dog - acrylic