United States Government Image Sources
When an author finds an image on a US government web site that would enhance a particular article, the author should use the image in an appropriate manner and provide a courtesy link to the involved agency. In addition, a note to the site operators should be provided that shows where the article is published. In some rare cases, an image prepared by someone not involved with the government may be present on a US web site. In these cases, it is your responsibility to ensure that you respect copyright. If you credit the source, you are exercising due diligence with respect to your publishing activity.
Images downloaded from government sources may be used by anyone for any purpose with the exception of government identifying marks. For example, authors may not brand their articles with logos that imply that their article has been prepared for or by the government or that it has been officially approved in any manner.
Some of the government agencies maintain web search facilities that can be queried for images. A number of these sites are listed below with descriptions. The use of these sites is acceptible for authors but the source of the image should be listed in the finished article.
US Fish and Wilflife Service
This agency maintains a web search at http://digitalmedia.fws.gov/index.php. They do include a copyright notice at http://www.fws.gov/help/disclaimer.html which mentions that some images may be the property of non-government entities. A standard notice of use should be acceptible for images received from this site.
Gov.com is a search portal that allows users to find information within the US government web servers. Included are images. Use their search tool to quickly locate images stored at various government agencies. The returned results may include references from state sites as well.
Whitehouse.gov is the informational site maintained on behalf of the president. Their search tool allows authors to find images stored at the Whitehouse web site and at other government agencies.
This site is another portal that authors may use to search for government images. The service will return material stored on federal and on state web sites.
Centers for Disease Control
The CDC maintains a large gallery of images that may be useful for certain types of articles. Their web site is located at http://phil.cdc.gov/phil/home.asp . There are no copyright restrictions as all of their images are in the public domain. A courtesy reference and notice is requested of authors using their material.
The NPS maintains a gallery of images that are connected with park operations. Many of these are general topic images. Use the search tool at http://npsfocus.nps.gov/npshome.do?searchtype=npshome
United States Department of Agriculture
Images of landscapes, crops and farming related themes are available at the USDA website http://www.ars.usda.gov/is/graphics/photos/cropsimages.new.htm and can be searched with their online tool.
National Aeronatics and Space Administration
NASA maintains a large collection of space photographs as well as many of ground based personnel. Find their search tool at http://www.nasa.gov/multimedia/imagegallery/index.html
Library of Congress
The LOC maintains a large collection of online images at http://www.loc.gov/pictures/ which includes many thousands of images collected over the years.
State Government Resources
Other Graphic Sources
Authors may use the advanced image search capabilities at Google. Use the advanced search tool located at http://www.google.com/advanced_image_search which allows authors to specify the usage rights desired. Select "Only images labeled for reuse" and limit images for "Commercial use" and "Modification". The modification attribute may be omitted if you do not intend to alter the image. Google will return a list of images matching your keywords. Check the images to see if one fits your need. The web site hosting the image will have a usage policy such at a notice that the "Creative Commons" license applies to the work. Include a source reference to the image in your finished work.
Anyone may use images stored at http://commons.wikimedia.org/wiki/Commons:Welcome provided that they follow the terms specified by the contributor of the work. In many cases, this involves a simple credit to the photographer and a courtesy email. There are many images available in the Wikipedia Commons and more are added every day.
Another free photo site, http://morguefile.com has a lot of images that are freely available. Other than claiming that the photos are your own work, you are free to do what you want with the images. You can use them in your Infobarrel articles. You can modify them. You can use them commercially. It is a great site to use. The search engine helps you find images that fit your topics.
Public Domain Photos.com
While not a new site, this one was only recently found via a Squidoo article: http://www.public-domain-photos.com Opinions about this site are welcome.
This article is a work in progress and it will be updated to include additional image sources. If anyone finds other agencies that are useful for authors, feel free to provide a notice of the web address. As mentioned above, the Internet is great for delivering images with articles. In order to engage visitors, authors should include at least one image, and likely more, with each of their articles. These can be created by the author themself or they can be sourced from various others. Using the free sources listed can be an easy and quick way for authors to get suitable images, improving their articles.