I program experiments in PHP/MySQL. Data can be passed to and from the database, allowing for conditional responses based on information provided by participants. Using PHP/MySQL provides an incredible amount of flexibility and customization.
In addition to running surveys and experiments, my webstudy site is also useful for facilitating class discussion. I recently developed a site for the Organizational Behavior core class, in which MBA students completed exercises in judgment and decision-making. The site captured MBA student responses to a number of commonly observed biases, generated class means, and automatically emailed students feedback on their performance. Students were able to follow the discussion with their own results in hand.
I have also developed a website that provides students (MBAs and Undergraduates) an opportunity to provide and receive feedback on their team- and leadership-skills. Students participate in a two-part online exercise. In the first part, students log onto a website and make (round-robin) self- and peer-assessments on a variety of behaviors and traits related to their team project and class work. In the second part, students log onto a website in which they receive feedback about their teammembers' assessments of them. The second website automatically calculates self- and peer-assessments for presentation to students, and the data (stripped of identifying data) can be downloaded to a spreadsheet for future analysis.
If you are interested in developing a WebStudy, I would be happy to help out. Contact me at brion at haas dot berkeley dot edu. .