It's exciting to watch the growth of various photo-sharing communities on the Internet. Images that would once have rested dormant in boxes or framed on walls are now online for the entire world to view. Yet popular attitudes that what is in the public eye is for public use make it highly likely that your posted images may be used and re-used without your permission—and without compensation.

If that's okay with you, then okay. But if you have any monetary interest in your photography, you should take the time to officially copyright your images. Although technically your photograph is protected at the moment you press the shutter, collecting damages is far easier if you have legally registered it with the US Copyright Office.

"Visual artists are at the eye of a perfect storm, and copyright is at ground zero," says Eugene Mopsik, executive director of ASMP (American Society of Media Photographers). "Both Congress and the public need to know that you value your intellectual property, and the best way to do that is to register your work... Don't wait until you are infringed and then possibly lose the available remedies."

ASMP has posted a step-by-step tutorial on how to register both published and unpublished works. The US Copyright Office is unveiling an electronic registration system later this summer, which will make it easier and even a bit cheaper to protect your single digital images. However, fees for collections and groups of works are likely to increase, ASMP reports, depending on the quantity of works in the collection.