Setting a min/max zoom for Bing maps in Silverlight

public class MyMapMode : Microsoft.Maps.MapControl.Core.MercatorMode
{
    public Range<double> MapZoomRange = new Range<double>(1.0, 10.0);
    protected override Range<double> GetZoomRange(Location center)
    {
        return this.MapZoomRange;
    }
}

you can try it!