When running the MVC 2 Areas example that has a Blog Area and Blog Controller the URL looks like this:
http://localhost:50526/Blog/Blog/ShowRecent in the format: >
Just to answer your original question, in case someone else is reading this:
Do not name your [default] controller blog. This is why you get blog/blog {area/controller}. You can either give it a completely different name: i.e., blog/view, blog/posts, blog/recent, etc. or, a default like home. in this case, if you also have home in your out-of-area controllers, you'll want to namespace your default controller:
routes.MapRoute("Default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional},
new[] { *appname*.Controllers" });
This will ensure that "/" and "/blog" go to the appropriate "home" controller. If you search for the duplicate home controller error you'll find more on this.