WSS 3.0 : How to add a new ContentType?

Here you go for the sample,

SPWeb MyWeb = new SPSite("http://<Server>/sites/Team%20Site/default.aspx").OpenWeb();

SPContentType DocTypes = MyWeb.AvailableContentTypes["Document"];

SPContentType MyType = new SPContentType(DocTypes, MyWeb.ContentTypes, "Test");

MyWeb.ContentTypes.Add(MyType);