I haven 't tried this, because I need my Mac for real work just now, including a stable Windows install for Parallels, but LOOK at this.
This claims to allow you to virtualize any Windows installation, over the network using Transporter. Meaning, as the author points out, if your organization has a customized Windows install (mine does) that you can move the whole thing over to Parallels without paying for new licenses for Windows, Offfice 2003 (I paid for both), etc.
Report back if you try this. At the moment I do not have an Intel Mac I can risk with experiments like this:
http://babygotmac.com/a/use-parallel...ndows-install/