I have used UNetbootin to create an installable / live bootable flash drive from Ubuntu 12.04. However that didn't preserve the normal Ubuntu boot menu which allows to me to enter advanced options. It has a custom menu that I can pick from predefined choices like "Install Ubuntu" and "Try Ubuntu without installing". What I would like is to be able to boot from the USB flash drive, but then be able to remove it from the computer once the desktop has loaded. The laptop I would like to use this on does not have an optical (CD/DVD) drive - nor do I have a USB version available.

What do I need to modify on the flash drive to add an option to "Try Ubuntu (RAM)" that passes the TORAM=yes parameter to the initrd options? Are their other things I need to touch/change as well? Is it even possible? I am not restricted to version 12.04 if that makes a difference.

Bonus: I would guess the answer would also allow for other options like acpi=off as well, but if it is different I would appreciate having that answer too.