count-up "odometer" system

We need an odometer animation for a web page created that will estimate the number of 'things' are customers are collectively doing (like calories burned or steps taken) that has the following features: * 'rolling' or 'rotating' numbers * initial value pulled from XML file on server (& updates when page refreshes) * "increment rate" determined by another value pulled from XML file on server - will be something like increment milliseconds (delay time between increments) (smallest increment will be 250ms, largest might be 5000ms) * will need to be usable for different values on the same page (i.e. ID the proper XML file to use to run the display) * needs to display up to 10 digits without any leading 0's We will also need some code on the server to keep the XML file up to date based on our estimated rate of increase for each item we are tracking. This would be a simple chunk of code that updates the file every N seconds with the old number incremented by N.