What is the easiest way to convert a physical Ubuntu (v. 10.04) into a virtual machine?
- Convert to VMware workstation image or
- VirtualBox image
You can use VMware vCenter Converter.
VMware vCenter Converter can run on a wide variety of hardware, and supports most commonly used versions of the Microsoft Windows and Linux operating systems.
Automate and simplify physical to virtual machine conversions as well as conversions between virtual machine formats with VMware vCenter Converter. Use the intuitive wizard-driven interface of VMware vCenter Converter to transform your physical machines to virtual machines.
For more info, and to download it visit VMWare
You can run Ubuntu in VirtualBox, via raw disk access. It will use a real disk as if it were a virtual disk.
To convert the disk into an image, see this answer.