Hi Todd, my action is slightly different from what you want so I won't send it to you since it will be harder to modify mine than to create a new one. But I think you can create one yourself really easily. Here are the steps in my action:
1) Resize the image, this very important because the size of the text depends on the dpi of the image. If you don't resize and some of your images are let's say 300 dpi and others 72 dpi the text will have different sizes when you use the action in batch. Even if the image is the correct size, resize it, or better yet, start with an image that is not the correct size. Start with a full size image and resize to 500 pixels wide (or whatever) and 72 dpi.
2) Create the text using the text tool. It will automatically create a new text layer. Make the text plain white and use a font that you like, shadow and transparency come later. Use the copyright symbol in the character map, your initials, etc. Adjust the size and position of the logo or copyright message.
3) Right click the text layer on the layer window and select "Blending Options". In blending options you can adjust transparency, shadow, etc. until you get the effect you want.
4) In the layers menu apply "Flatten image".
That's it! You can now batch proccess and add the copyright symbol all images in a folder. You will however need another action for vertical files (in which you resize to 500 pixels high, not wide). I think you can copy the action and change only the resize step, but I don't know how to do that. Maybe someone with more photoshop knowledge will help me out here.