Moving Keychain passwords in bulk. Possible?


I have a new MacBook Pro which has replaced my dying 2007 Black MacBook.

MacBook is running Lion. MacBook pro is running Mountain Lion.

I have a large number of wi-fi and other passwords stored in (I assume) Keychain on the old machine, which automatically connected to wi-fi networks in places that I travel to regularly. Local library, family, hotels, friends etc.

Is there a file I can transfer across from the old laptop to the new that would save me the task of finding and re-entering everything?

I haven't tried looking yet, as I would expect that copying a password file would be one of the elementary security precautions installed. But if it's possible, it would be useful.