This article will present an overview of the way that the Internet is being used to assist psychological research and mediate psychological practice. It will show how psychologists are using the Internet to examine the interactions between people and computers, and highlight some of the ways that this research is important to the design and development of useable and acceptable computer systems. In particular, this introduction will review the research presented at the recent International Conference on Psychology and the Internet held in the United Kingdom. On behalf of the organizing committee, the author would like to thank all psychology researchers and practitioners who presented and participated in the conference. The final part will introduce the eight articles in this special edition, including those from the invited speakers at the conference: Tom Postmes, Pamela Briggs, and Ulf-Dietrich Reips. The eight articles are representative of the breadth of research being conducted on psychology and the Internet: There are two on methodological issues, three on group processes, one on organizational implications, and two on social implications of Internet use.