An internet linking method includes providing plural-bit sampled values representing media content at a user's computer. This digital data is passed to a processing system, and an identifier of the media content derived from the sampled values is returned from that system. This derived identifier is used to index a database, from which a corresponding URL address is obtained. A link can then be established to that URL address, and information obtained from that address can be presented to the user. A steganographic decoding technique can be used in the processing system to derive the media content identifier. A variety of other features and arrangements are also detailed.