GIMP Plugin Registry

'watermark' by Doug Reynolds allows the user to add text as a watermark into an image. The watermark text is done as a lighter overlay of the background of the image. Besides the text itself, the user can choose the font from a pull-down menu, size (in pixels), location (one of the four corners), and opacity (in percent).
After installation the plugin script is availbe under the menu: Script-Fu/MyScripts/Watermark.