The third Gordon Research Conference on the Physics and Chemistry of Microfluidics will focus on the discovery and advancement of the science that underpins the development of microfluidic and nanofluidic systems, as well as, new exciting applications of these systems in areas such as single molecule measurement and nanobiotechnology. Gordon Conferences are deliberately smaller, more intimate meetings with less than 150 people in attendance. In the past, this has been a dynamic conference with enthusiastic participation by all speakers and attendees. If you have not previously attended the Microfluidics Gordon Conference (Oxford 2001 or Big Sky 2003), we know that you will find it to be a unique experience with an atmosphere that is both exciting and stimulating. The first two conferences in this series were very successful with thought-provoking formal sessions on important subtopics in our field, and informal unstructured time used for stimulating discussions amongst all participants. It is an excellent forum for junior scientists (including graduate students and post doctoral fellows) to interact closely with the more senior researchers in our field.