You can manifest from the Ethereal Plane with a moment’s thought.
Prerequisite: Ability to manifest from the Ethereal Plane to the Material Plane.
Benefits: Once per round, you can manifest from the Ethereal Plane to the Material Plane as a free action. Turning ethereal still requires a standard action.
Normal: Without this feat, manifesting from the Ethereal Plane requires a standard action.
Source: Libris Mortis, page 29.