from the website
This action sequence generates a demo dataset and renders the chart based on that data. At the Google I/O 2009 Sandbox, Pentaho demonstrated integrating an Inline ETL process with access to a Google Docs Spreadsheet.... whatever that means.
Nonethe less it looks cool and would make for a great school project.
It uses the LeJOS firmware and 2 NXT (presumably to allow for the 5 independent bars)
via Make Magazine blog