In the "early" days we had to use third-party applications to maintain multiple iPhoto libraries. With iPhoto 08 Apple has given us the tools we need to do it in iPhoto.
In this screencast, we'll show you how to manage multiple libraries
Aperture 2, Apple's groundbreaking photo editing and management software, gives photographers powerful tools to manage massive libraries, speed through photo edits, make essential image adjustments, and deliver photos online or in print with ease. Whether you're a professional photographer or a photo enthusiast, Aperture delivers a simple, integrated workfl ow that takes photos from import to output with uncompromising quality every step of the way.