I don't worry about watermarks on the picture as much as I worry about embedding it in the picture. As soon as I take photos off of my camera I embed my copyright information in the image. This means that if someone saves it and edits out my watermark on the image, my contact information (website, city, and business phone # for me) are still in the image. You can't take that out. If they were to save all of my photos on a CD and take them to a lab, my copyright information is still there and the photos should not be printed. I feel safer with that there.

I do think it's a little silly to watermark at all if you are not looking to sell your photos, but I can understand the concern. I go back and forth as to whether or not my photos will have a watermark just to post on forums, but my information is always embedded in each and every photo I post. I just started my website where you can purchase my photos online (although the prices aren't up there yet but will be soon) and I have my information embedded in the photos AND a watermark with my website name on it. I did that for several reasons, but one is because the photos show up larger on this website than if I had resized them myself and I don't want anyone to make a small print from it.

But, then again, I am a "professional photographer" (though that still seems odd to me!) and I am now doing engagement photos, weddings, etc. and I feel like I need to protect my images very well.