I prefer the idea of booting from a USB flash drive or Hard drive for linux distro's
Booting from USB is quite helpful because it's not intrusive on your main system although it can be painfully slow when booting.
CD2USB is a good way to go with Ubuntu giving the ability to save any changes.
I don't really see the purpose (apart from the fact that you can say I did it!!) of overloading ones 'puter with vmware .. unless you want to switch between OS's whilst working. I assume that it will slow things right down unless you are only doing "text input", but then as yet I haven't gone down that root to be able to judge .
take a look at
http://www.pendrivelinux.com/ for usb boot and
http://hacktolive.org/wiki/Cd2usb for making a Ubuntu or super ubuntu install to an HDD on usb adapter
For DSl through the pendrive link
http://www.pendrivelinux.com/all-in-one-usb-dsl/