Level of USD vs EUR for last 40 hours

Values shown are USD per 1 EUR, Data is pulled from Google Calculator API on the hour and stored on the Node.js server... connection to the server is by WebSockets (where supported) and falls back to flash sockets/XHR multi-part etc... utilising socket.io library

The end benefit being the chart updates itself without having to poll the server, the server will push the new data to the client (this web browser) when it is available.