What are the technical and license restrictions around virtualization for Leopard, Snow Leopard and Lion? I have a 500 GB hard drive on my MacBook Pro. I have OS X 10.7 (Lion) on my main partition and Windows 7 Ultimate on a secondary partition. Because I have older applications that I would like to run in OS X 10.5 (Leopard), I was thinking of creating an additional partition and install either Leopard on it. This raises the following questions: 


What are the license restrictions on doing this type of install if I
own all the software?  
What are the license restrictions on using virtualization tools like VMware Fusion to access these partitions? I have read the only OS X Leopard Server was allowed to run    virtualized, but I cannot seem to find an authoritative answer on
this. I do not have Leopard Server, but regular Leopard.
Are these license restrictions different in Snow Leopard?


And then, there are the technical questions, like: Does VMWare even allow for me to access, say virtualized Lion from Leopard or virtualized Leopard from Lion? I know I can get to the Windows partition from either one, but I have never tried any OS X virtualized. What are your thoughts? Thanks.
Legally, you can only run OS X Server in a virtual machine for 10.5 and 10.6. With Lion, they allowed regular OS X installations to run in up to two virtual machines. VMWare Fusion does support Leopard and Snow Leopard Server virtual machines (but not yet Lion), but I don't know if it will let you use the same installation both booted from disk and in a virtual machine.