Enhanced Silverlight Graphs

We have an internal website written in VB.NET using the Microsoft Chart control (.NET 3.5) to generate graphs of our time based data, retrieving it's data from a SQL Server database. We would like an enhanced graph control, something akin to the interactive charts found on Yahoo or Google's financial pages. These charts display an entire dataset at low resolution, but then when zoomed in fetch (asynchronously) new data to display data at a higher resolution. For example, over a year it may display a line graph with 52 average weekly values, zoomed in to a month, it may show 31 daily values, zooming to a week, may show hourly, etc etc We are currently using the Google Visualization API to deliver our charts. We expect similar behaviour to the 'Annotated TimeLine' graph - see [login to view URL] for more details. Project deliverables: VB.NET with Silverlight front end graph control on web page demonstrating ability for the user to zoom/scroll along time axis across all data. Ability for the user to add/remove series, add/remove trend lines, rescale axis. Written using Visual Studio 2005/8 in a project form with all source code commented so that I will be able to extend, maintain and adjust funtionality in the future.