What is the best way to consolidate two iPhoto libraries into one library? On the family's iMac my wife and daughter have separate user accounts, each with their own iPhoto library. My wife has asked me to consolidate both libraries into a single library for convenience.

What is the best way to do this? Can it be done with the existing software and utilities that come with Snow Leopard or is there a 3rd party utility that facilitates the process?

Thanks in advance.
There's a third party application named iPhoto Library Manager which seems to have a good reputation for merging, splitting and generally managing your iPhoto Library: