I require a Silverlight application that will allow a PC with an attached scanner or MFP/AIO initiate scans (WIA, TWAIN over USB) directly from Silverlight. In addition, the Silverlight application must be able to use MOSS 2007 web services APIs to place the scanned image into the selected SharePoint library / Worlflow. An additional benefit would be to trigger a metadata entry process within Silverlight, with data entry fields presented dynamically based on the SP destination workflow, but this can be a future effort to keep the cost down. I would prefer that the handling of the local USB scan interface is done through some HTTP policy / listening port method that is fairly standard for Silverlight, so  that the design is flexible and capable of supporting other transports such as scanning from a network device over Wifi.