Is there any free downloadable programs that will allow me to add a watermark copyright to my pictures? I have the program Aperture with my Apple...I have searched the help menu and it says I can add a watermark by creating one and saving it as a photoshop file. I do not have photoshop. Any suggestions...

Hello everyone!, ..love this site lots of info. My question is this. I have a fantastic shot of lightning in the background of a famous national monument.Its a great shot and have had great demand for enlargements. Do i need uncle sams go ahead on this? What kind of release do i need ?if any. Thanks...