I'm not an Ubuntu user but I do believe that the Ubuntu folks have plopped a package for
VirtualBox OSE into one of their repos. Don't ask me which one.
I installed it for my father-in-law who is using LinuxMint. I installed it primarily so I
could create a Windows XP virtual machine since my father-in-law is a recovering Windows user.
:) Although I didn't use it for an extended amount of time, I really didn't notice much
difference between the OSE edition and the commercial version... although yes, there are some
features that aren't there.
Your comment made it sound like the OSE edition was basically unusable and missing all useful
features. That is certainly not the case. Also, if I remember correctly the Ubuntu package
had "VirtualBox" as part of the name. Have they made a special agreement with Sun? I don't
know but I doubt it.