just write a good route for yourself
routes.MapRoute(
"Default",
"{controller}/{action}/{name}/{id}",
new { controller = "HelloWorldController", action = "Welcome", name = UrlParameter.Optional,id=UrlParameter.Optional }
);
the params will be mapped accordingly; these are also called SEO friendly url's
Try this link as well http://weblogs.asp.net/scottgu/archive/2009/10/13/url-routing-with-asp-net-4-web-forms-vs-2010-and-net-4-0-series.aspx