As some here know, I'm a big geek. My background is computer engineering, as well as intellectual property law (kind of explains why most of my posts are incredibly long (law) and nonsensical (have you ever read a computer manual?). In the interest of helping inform our members, what happened here is a pretty common misconception with respect to copyright law. As Bill points out, just because a picture appears on a web site does not push that picture into the public domain from a Copyright law perspective. This is true even if no copyright claim is made on/in the picture itself or the surrounding web page. A relatively recent change in U.S. law has made it so that Copyright rights are inherent the moment a form of expression (writing, picture, etc.) is reduced to tangible form, and thus copyable. This gives "authors" (the generic term used when talking about copyrights) the ability to more readily protect their works. Even though a use such as the one above is likely to be seen as de minimus, and therefore not eating into the author's rights, it might be better to provide a link to the web site containing the picture or other information, or, as Bill suggested, contacting the web site owner to get permission to reproduce the picture or other work.
HTH!