Want to copy "places" from one event to another

I took some photos with my cellphone, which supports "places" in iPhoto. My husband took some with his camera at the same event. I have them all on my computer in my iPhoto. I would like to copy the "place" to all of his photos so that they will all be labeled properly. Is there an easy way to do this? I sure don't want to have to manually label each one. Any and all help is appreciated! Thanks!