Key for boot menu

[monnier]

Which key brings me to the boot menu where I can choose which device to boot from? I don't mean F2 to get to the BIOS, just the key to choose the boot device for this one boot rather than to change the default order.
[It's F8 on my ASUS motherboard, F12 on Thinkpads, and F11 on my MSI Wind, so I tried those keys, but none worked. I wish there was a bit more
rationality behind the key choices]

[irads]

As far as I know, selecting boot device on-the-fly is not supported in BIOS.

[monnier]

As far as I know, selecting boot device on-the-fly is not supported in BIOS.

Are you sure? It'd be the first time I own a machine where this is not supported. Can you at least keep it as a feature request (and if it depends on Phoenix, pass it on upstream to Phoenix?)