The built-in component named uiComponent provides a magic map of UI components. If you were looking for the component id register:nameField:name, you would use the following EL expression:
You could also inject this component as a Map
@In Map<String, UIComponent> uiComponent; UIComponent c = uiComponent.get("register:nameField:name");
As for a convenience method in Seam, yes, it would be helpful if there were a couple of more utility methods for more sophisticated lookup. Check the RichFaces API for such a helper class.
Thx for your help Dan!