Is there anything wrong with using two 1-way switches to create a lighting circuit that can be turned on from either of two locations?
i.e.
Live splits into two paths. Both are controlled by a one way switch, and both end up at the light. So if either or both switches are on, the light is on, if both switches are off, the light is off.
i.e.
Light | | Sw Sw | | \ / | Live
Ben