With the recently released iPhoto 9.3, Apple made it much easier to maintain separate iPhoto Libraries.
This is great news for people with large photo libraries, because you now have the ability to divide your photos into separate iPhoto Libraries instead of maintaining one giant bloated library that your Mac may not be able to open properly.
Coming soon, you will be able to take advantage of this in Silent Sifter as well. We heard your voice, and we are upgrading the system to allow multiple iPhoto libraries at any location. This will allow you to structure your iPhoto libraries however you choose – by year, by camera, by type, etc.
All you need to do is add the iPhoto library is an input/output and then build filters to restrict which files go into or out of the given iPhoto Library.