JSON to dynamic object function

Implementation.cs

private static dynamic CreateDynamicFromObjectGraph(object input)
{
    if(input is IDictionary<string, object>)
    {
        var result = (IDictionary<string, object>)(new ExpandoObject());

        foreach (var pair in (IDictionary<string, object>)input)
            result.Add(pair.Key, CreateDynamicFromObjectGraph(pair.Value));

        return result;
    }

    return input;
}

Usage.cs

var json = new JavaScriptSerializer();
dynamic obj = CreateDynamicFromObjectGraph(json.DeserializeObject(someJson));