iPhoto Problem

I've recently bought a NAS drive and have moved all of our music files so that both myself and my wife can access them through iTunes on our laptops (Powerbook & iBook).

What I really want to do is move all of our images to the NAS so that we can both have access to each others photos. The trouble is the way iPhoto files the images in date order which makes it difficult to merge our libraries, it could take hours as we both have a couple of thousand photo's some are duplicated.

Is there a quick way to merge both sets of photos and have a single library document so that if either of us uploads a new photo it will appear on both the laptops?