National and state educational initiatives are increasingly prioritizing computer science and computational thinking as valued sets of skills and practices. However, despite ongoing efforts to broaden participation in computing, the field faces increasing underrepresentation of women and other racial and ethnic groups. In this paper, we argue that physical computing can provide rich, varied entryways into computing practices, and that kits that support social or collaborative use may be more compelling for underrepresented groups. We present the design of a scaled-up physical computing kit, called StegaCircuits, which we created to foster more social, exploratory introductions to computing. We present preliminary data collected during user tests at a Maker Faire that suggest StegaCircuits supports social introductions to physical computing through multi-user interaction. Finally, we highlight promising facets of the design that may positively impact cognitive and emotional responses to computing fields.