In addition to the social and fun aspects of Flickr, the site can also be is a fantastic resource when searching for low-cost photographs for use outside of the photo-sharing site.

Many photos on the site are licensed under Creative Commons licenses, which may permit you to use the photos for non-profit and, in some cases, commercial purposes.

When you are viewing images on Flickr, Creative Commons licensed content includes a small note beneath the Additional Information heading (see the image to the right for an example). The icons represent the different components of the licenses.

Once you have found an image, you can use it as long as you abide by the license’s conditions. Sometimes that means simply providing an attribution (a visible credit) with the image (Attribution). In other cases that means sharing your work under the same license (Share-Alike). Flickr has more information, or you can visit the Creative Commons to find out more.

Of course, it would be great if you could search Flickr for Creative Commons images. The folks at Flickr thought the same thing, and Flickr’s advanced search function has the ability to limit your search to photos that are Creative Commons licensed.

It’s also considered a courtesy to send a quick “thank you” message to the photographer letting them know about your use of the image.

Two quick words of caution, though.

You should take care to avoid images where there may be a copyright or trademark violation - for example, a screenshot of a website, a digital copy of a famous photo etc. may be posted without the original copyright holder’s consent.

The other thing to bear in mind is that when a photo contains people, the photographer may not have obtained “model releases” from each of the participants in the photos. So even though the photo is licensed under Creative Commons, the people in the photo may not have given permission for their image to be used for commercial (or other) purposes.

This problem is eloquently described by Jason Garber on Flickr: Virgin Mobile misappropriates likenesses. In it he shows how an advertising agency used a Creative Commons licensed work in an advertising campaign, and the people pictured in the photo were not impressed.

The easiest way to avoid this problem is to not use photos with people in them, or to use shots where the individuals are not clearly identifiable. But if you really want to use a shot that has individuals in it, make sure you double-check with the photographer that your use is acceptable to the people depicted. If they can’t contact those people, or are unsure, best not to use with the photo.

Update: The SMH reports that one of the folks affected by that Virgin Mobile campaign is suing… (thanks Chris!)