I have been creating LiveUSB images and had great success is most cases lately with F11 x64.
One issue seems to be reproducible.
On some computers, when I boot with a LiveUSB x64 F11 I get the same screen resolution options I would have with a typical OS.
On some systems, I get results that are less desirable.
Example the Dell I am on at the moment only offers screen resolutions of 1024X768 or lower. The video card on this system is an Nvidia 8300GS and on another system using an Nvidia GTX260 I get the expected gammut of screen resolution choices using the same LiveUSB drive.
When I searched the LiveUSB drive for xorg.conf the file is not found.
So, Where does the liveUSB F11 x64 OS obtain it's video configuration information from? I would love to modify a file or setting so that I have the higher choices available.