The world-wide-web offers a potentially interesting tool to collect data from a large and heterogeneous audience. While questionnaires have become rather common on the Internet, its potential reaches far beyond text processing. In principle, it is not only possible to perform interactive experiments on the web, they can also include graphical animation and time critical responses, such as reaction times. We implemented a visual motion extrapolation task on the web using the programming language Java, which can be interpreted by standard web browsers such as Netscape or Internet Explorer. The data collected with this method turned out to be reliable and differed little from data obtained in a controlled laboratory setting. Thus, the web can - generally speaking - be used for data collection of large samples sizes. The strengths and weaknesses of interactive visual simulation experiments on the Internet are discussed.