SS/SE Same FOB for two Prius

I saw something on-line a while back that indicated that the key fob could be keyed to operate two different Prius automobiles (owned by the same household).

That person and his wife each had a Prius but they wanted to be able to use the same key fob for both cars.

Unfortunately I was unable to find the reference again.

I currently have a 2005 Prius and my wife has a 2006 Prius on order. How do I go about getting the same key fob to work for both cars. The local dealership was clueless with regard to this request. They said I would have to purchase a new ECU. That response was a non-stater for obvious reasons.

Can anyone point me in the right direction?