Help! I would finally like to start a website...the only thing holding me back is the whole copyright thing. I know I can use photoshop to write my name on my photos, but I would like to be able to post my photos online where people could NOT right click and copy the photo, then right click and paste...

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...