I read the threads on the VM software out there but didn't see one that answered what I was wondering. I am new to virtualization software so am a bit cautious with this whole thing. I am not sure either to get Fusion or Parallels for my 2010 13" C2D MacBook Pro. This is a list of what I want/need and if someone can tell me which is my best bet, I would greatly appreciate the responses. -I want to run Windows inside OS X so I can access Mac and Windows programs simultaneously. -I would love to install Windows on an external hard drive so I wouldn't need to partition my already small internal hard drive. So whenever I need to use Windows I just plug in the external and use it. -Also would USB or firewire be best for the external hard drive? Thank you!