dd, physdiskwrite/physgui, image writer for windows, whatever you want.
I use ISO images more since I do a lot of development work with VMs more than physical hardware, but so many new systems are shipping without CD drives that the USB stick images will be very handy for more and more people using physcial hardware.
In either case (iso or memstick image) if you are booting from USB, such as a USB DVD-ROM, you may need to press the boot menu option that says it's for use in booting from USB. This sets an increased boot delay that will allow the system to catch up and detect USB media before trying to mount it.