This virtual desktop manager lets you have multiple desktops, and you can have different windows and applications running in each desktop.
Moving your virtual machines into Parallels Desktop view it
Create an Ubuntu virtual machine with VMware Workstation view it
VirtualBox makes it easy to create virtual machines. view it
Create an Ubuntu virtual machine using VMware Workstation. Part 2. view it
You can use Virtual Network Computing (VNC) to connect to your Mac view it
You can have cool, desktop effects with Desktop Manager on your Mac view it