Electric Price Tags are a realization of a mobile system that is linked to technology in physical space. The underlying theme is that being mobile can mean far more than focusing on a portable device�it can be the use of that device to unlock data and technology embedded in the environment. In its current version, users can reconfigure the price tags on a store shelf to display a desired metric (e.g., price, unit price, or calories). While this information is present on the boxes of the items for sale, comparisons would require individual analysis of each box. The visualization provided by Electric Price Tags allows users to view and filter information in physical space in ways that were previously possible only online.