In one aspect, a user captures an image of a physical object (e.g., a grocery item) with a smartphone. The depicted object is identified, such as by extracting fingerprint or watermark data from the imagery. Other imagery depicting that object—or depicting related objects—is identified on the web, and is displayed to the user on the smartphone screen. The user may select one or more of these images and direct that they be posted to a social network account (e.g., Pinterest) associated with the user. In another aspect, the user's location is sensed (e.g., an aisle of a department store), and a collection of images depicting nearby products is presented to the user for selection and posting to a social networking service. A great variety of other features and arrangements are also detailed.