Are there any Android distributions that can boot to a different environment depending on what code is entered at boot time? And said partitions are hidden from

Are there any Android distributions that can boot to a different environment depending on what code is entered at boot time? And said partitions are hidden from each other (i.e. once booted, the other partition is impossible to detect)? This was described in Cory Doctorow's "Little Brother" novel, and on the face of it seems like a reasonable proposition - any major flaws in such a plan?