Run a Windows Virtual Machine on Mac OS X 10.8 with a real Hard Drive partition
Both the paid virtualization apps, VMWare Fusion and Parallels Desktop for Mac, allow you to boot the Windows partition from within OS X. You could also do this manually with the free Virtualbox solution, but it's a bit tedious and I'm not sure if it works reliably.

For instructions on VMWare Fusion and Parallels, see the below, respectively:
Launching your Boot Camp partition in VMware Fusion
Can I run my Boot Camp partition with Parallels?