This chapter explores the promise and pitfalls of using the Internet as a tool to collect data, with a focus on practical and conceptual concerns relevant to social-personality psychologists. It discusses some of the benefits and challenges of collecting data over the Internet, and focuses primarily on using the Internet to recruit participants and collect data. The chapter reviews a practical guidance for implementing online studies. It provides detailed examples of how common study designs within social-personality psychology can be successfully implemented via the Internet. Using an experimental design in an Internet-based study requires translating the random assignment process and the experimental manipulation(s) to a Web-based format. The chapter highlights a few unique options and challenges of Internet-based study design. It also discusses a few but unique ethical concerns which the Internet data collection presents before ending with a discussion on the future opportunities for Internet use in research.