The presently claimed invention relates generally to methods and apparatus employing digital watermarking. Once claim recites an apparatus including: electronic memory for storing received digital imagery or audio, in which the digital imagery or audio comprises digital watermarking including a first instruction, in which the digital watermarking is hidden in the digital imagery or audio through alterations of data representing the digital imagery or through alterations of data representing the audio; and an electronic processor programmed for: decoding the digital watermark from the digital imagery or audio to obtain a first instruction; and based at least in part on the obtained first instruction, updating said apparatus when an address associated with the digital imagery or audio changes. Of course, other claims and combinations are provided too.