Another site you may enjoy is
The images are free to use non commercially but some do require you to notify the artist of the use you will put it to via the attached comment button. Some commercial uses have been approved. A great site for photos. It is divided up by subject and takes ages to browse. It is free to join and you can save images, both your own and others that you may want for inspiration or collage etc.,to your own private or public portfolio once you join.