I had my first experience with UEFI Secure Boot about a month ago, when I bought my new Packard Bell laptop, which come with Windows 8 pre-installed. The only way to boot other OSes (I am Linux user more than 10 years, so it wasn't even an option to run Windows everyday), was to disable UEFI boot at all and switch to "Legacy BIOS boot". There was an option to disable secure boot in UEFI in BIOS, but that option was disabled itself.