In photoshop 7, select the Action tab, Click on icon for create a new action.
Name it something like "Create copyright text".
Open a file you want add the text to.
Create a new text on the image.
Save the image to a new file.
Stop recording by clicking on the stop icon.
Now open the menu, File->Automate->batch.
Select the action "Create copyright text"
Select the source folder of your images
Select the "Override Action Open Commands" checkbox.
Selecte the output folder.
Select the "Override Action Save As Command" checkbox.
Select the "OK" button, and watch photoshop play with your images... http://www.lufk.nu