Writer Andrew Kantor has published an article for USA Today covering your rights as a photographer.
What I discovered is that a lot of people have ideas often very clear ones of what is legal and what isn't, based on anything from common sense to wishful thinking to "I always heard "
Trouble is, they aren't always right. If you've got a digital camera and like to shoot in public, it pays to know the real deal.
The USA Today article covers the topic nicely. If you'd like to know more, Kantor has also published a PDF cheat sheet on the laws covering photography available for download from his weblog.
While we're not all professional photographers (or at least I know I'm not), it is important to know your rights. If you take a lot of photos, this information is worth knowing.