New Old Stock aggregates and displays images from Flickr with most (if not all) images being under the Creative Commons License (author assumes). Author also creates photo packs that are for sale. The images are amazing, and sometimes exactly what is needed for a presentation! The downside is the search options, whicr are very limited (and frustrating).
You can download the image by clicking on it, and it will open the image in a lightbox the image can be saved with a right-click. Tip: the title of the image on the main page is a link to the original Flickr library where the image was posted.
There is a search option in the upper left which is helpful since there are no categories or any other organization. It’s not clear on how often a new image is posted.
Here is a sample of some of the images available: