Booting with EFI
One of the ways in which EFI is *actually* better than BIOS is its native support for multiple boot choices. All EFI systems should have an EFI system partition which holds the OS bootloaders. Collisions are avoided by operating system vendors registering a unique name here, so there's no risk that Microsoft will overwrite the Fedora bootloader or whatever. After installing the bootloader the OS installer simply sets an NVRAM variable pointing at it, along with a descriptive name and (if they want) sets the default boot variable to point at that. The firmware will then typically provide some mechanism to override that default by providing a menu of all the configured variables.
This obviously doesn't work so well for removable media, where otherwise you'd have an awkward chicken and egg problem or have to force people to drop to a shell and run the bootloader themselves.