Carl Pillot, Greg Scontras, and Lauren Clemens have developed response-time recording functionality for the web-based experiment software Experigen (Becker & Levine 2010). This functionality is included in the latest build of Experigen, which can be downloaded for free through the following link: Experigen.
For a start-to-finish guide to developing your own experiment using ExperigenRT, download this file. In it, you will find a ready-to-use experiment template, together with instructions for modifying the template to fit your needs (SETUP.txt), and a guide for publishing the experiment on the Harvard webspace (HOW_TO_SET_UP_FAS WEB_HOSTING.txt). You will also find the code for retrieving the results of your experiment using the statistical software R (getresults.R).