Flickr gives you access to images its like an online photo album. You can search for images by categories. I found this program simple to use like all programs I am sure that as I use the program more I will utilise more of its features.
I can see that this would be a useful program to use in the classroom. In my context I can imagine introducing the topic sea animals on the interactive whiteboard using photos from Flickr. It would give some of the students who have not seen the ocean a visual picture of what a beach, fish, turtle etc look like.