An experimental investigation of fluid flow in extremely small channels is presented. Potential applications for such channels include cooling of electronic circuits, and reactors for modification and separation of biological cells. The immediate goal is to determine at what length scales the continuum assumptions break down and if the Navier-Stokes equations adequately predict fluid behavior. In order to accomplish this, experiments are being conducted in progressively thinner flow channels. We have constructed three channels of rectangular cross-section ranging in area from 7200 to 80 square microns, utilizing the recent advances in microfabrication. In this paper, preliminary results are reported pertaining to friction measurements. It is found that in the relatively large flow channels the experimental observations are in rough agreement with the predictions from the Navier-Stokes equations. However, in the smallest of the channels, there is a significant deviation from the Navier-Stokes predictions.