KNIME, the Konstanz Information Miner, is a visual platform for graphically building and editing workflows and data analysis pipelines from defined components called nodes. KNIME is developed in Prof. Michael Berthold's group at the University of Konstanz, Germany. It can be downloaded for free from www.knime.org. KNIME is built on the Eclipse Interactive Development Environment and written in Java. Versions are available for Windows, Linux and now the Macintosh!
Just to get you started there is a tutorial here..