Can I Boot VMWare or Parallels from an internal OS X hard drive? The SSD on my MacBook has 4 partitions, each of which has a bootable installation of OS X. Is there any way to boot from one of these partitions with a virtualization app? I don't want to create an image from it, just boot directly to the drive within an app. 

It looks like Parallels and VMWare will only boot from images. I want to boot directly from the existing partition on my HD.
Parallels Desktop 8 can run Windows from a Boot Camp partition.

Getting Started With Parallels Desktop (PDF)

VMWare Fusion 5 can also run Windows from a Boot Camp partition.

VMWare Fusion Overview

I believe Boot Camp support is available in earlier versions of both products, but it's definitely in the current shipping versions.