I just downloaded Unity 3 to give it a try for my new project. The documentation states that this version allows Registration by Convention using the container.RegiserTypes method. But I cannot find this method anywhere. Am I missing an additional DLL? I used Nuget to add Unity 3 to my project.
How did you get the DLLs and are you sure you have the correct version of Unity? I added the dependency using Nuget and it worked once Microsoft.Practices.Unity was included. Version is 3.0.0. RegisterTypes is an extension method defined in UnityContainerRegistrationByConventionExtensions which may be the cause of your issue if you just added a reference to IUnityContainer and UnityContainer.