Nixy, I've seen you mention Parallels a few times. If you're going to do that, also consider VMWare Fusion, the major competitor to Parallels. They both do the same main thing, although some of the details are handled a bit differently, and either one may be able to do one or two things the other can't. Fusion usually comes out on top in the comparison reviews I've read, although it's been very close.
http://www.vmware.com/mac
Note that with Fusion--and I'm pretty sure Parallels does this, too--you can combine the virtual machine with BootCamp. That is to say, normally, when you install Fusion or Parallels, you create a virtual machine and install Windows on it. However, you also have the option of telling Fusion or Parallels to use your BootCamp partition as the virtual machine. Thus, when you boot OS X, and run Fusion or Parallels, it's really starting your BootCamp Windows in a virtual machine. This allows you to create just one Windows installation on your Mac (the BootCamp partition), and use it either natively (by booting directly into Windows at startup) for maximum performance and compatibility, or virtually, with Fusion or Parallels, to give you quick and easy access to Windows from within OS X, without having to install and configure the Windows OS and Windows programs twice.
Be advised that if you go this route (using your BootCamp Windows partition as your virtual machine's Windows as well), pay close attention to how Parallels or Fusion tells you to activate Windows. Windows thinks it's running on two different computers (one the BootCamp, the other the virtual machine) if you do it this way, so it can be tricky to get it to stop asking you to re-activate it every time you start Windows.
However, note that unless you need the full performance ability of the computer to be dedicated to running Windows OS and Windows programs, you might not need to use BootCamp at all. For office and productivity apps, using Fusion or Parallels should be fine. BootCamp is really only necessary now if you need to run full-screen 3D games.