I'm glad you found it helpful, David. Since writing this article I've discovered that Flickr is another place to get great free imagery.

There's even an easy way to search and sort for pictures that are under CC:

1. Perform the search you want.
2. Click the "Advanced Search" link next to the big blue Search button.
3. Scroll down and check the "Only search with Creative Commons-licensed content" box.
3. Hit the Search button at the bottom of the page.

Happy blogging!