I've had lots of macs, and every powermac/macbook/macbook pro/mac pro has a very obvious power button conspicuously placed. So.... huh? Even the phones/ipads/

I've had lots of macs, and every powermac/macbook/macbook pro/mac pro has a very obvious power button conspicuously placed. So.... huh? Even the phones/ipads/ipod-touch have the sleep/power button on top. The only product I know of that doesn't have a power button at all is the classic ipod.