Foter it's a great option for web design. It uses the Flickr API and searches Creative Commons photos. It doesn't only allows you to download the images directly to your computer, but also has an official WordPress plugin so you can search and insert photos directly from your CMS. In addition, it allows you to modify your embed code to resize the image as well as select the position you want them, so you just need to add it to your site by copying the shortcode. The shortcode already contains all necessary CC attribution,is mandatory to include, so you do not need to contribute authors manually.
Undoubtedly a good option that is worth taking for its practicality and easy to use.