The present technology concerns improvements to smart phones and related sensor-equipped systems. Some embodiments relate to smart phone-assisted commuting, e.g., by bicycle. Some involve novel human-computer interactions, e.g., using tactile grammars—some of which may be customized by users. Others involve spoken clues, e.g., by which a user can assist a smart phone in identifying what portion of imagery captured by a smart phone camera should be processed, or identifying what type of image processing should be conducted. Some arrangements include the degradation of captured content information in accordance with privacy rules, which may be location-dependent, or based on the unusualness of the captured content, or responsive to later consultation of the stored content information by the user. A great variety of other features and arrangements are also detailed.