So I want to virtualize the Win7 Boot Camp partition on my soon-to-be-retired work Macbook 2,1, because there's a tool I use occasionally that's hard to set up right and I don't use it often enough to remember how it was originally done.
VMware has a tool that can virtualize a running machine over the network. Doesn't work with a Mac's GPT partitions.
So here's the procedure that worked for me:
1) Install a utility called disk2vhd on the Macbook's Win7 install. Make sure you have less than 50% of the partition in use.
2) Run disk2vhd and then copy the resulting .VHD over the network to the VM host machine.
3) Create a new VirtualBox VM. Remove the SATA controller, make sure the IDE controller's set to emulate a PIIX3 (x4 might work, ICH6 definitely does not), attach VHD to the IDE controller.
4) Should boot.
If it doesn't boot at this point, you might have to convert the VHD's GPT partition table to MBR. I downloaded SystemRescueCD, attached the ISO to the virtual machine, booted from it, then ran gdisk using this tutorial:http://www.rodsbooks.com/gdisk/mbr2gpt.html
Since I'm using VMware for all my other work VMs, I'm going to try converting the VirtualBox VM over next.
 MS Virtual PC can't deal with VHDs created from a disk that's bigger than 137GB and VMware Player can't directly use VHDs. VMware's aforementioned virtualization tool can import VPC VMs, but again VPC can't see those big disks. This was a huge pain in the butt!