@Patrick, With[{acc = Prepend[Accumulate[Length /@ form], 0]}, Inner[Take[values, {##}] &, 1 + Most[acc], Rest[acc], List]] (borrowing Pickett's variables)

@belisarius Ah, sorry I missed you - just popped in to scan for interesting code snippets...

@MichaelHale's answer is closest to mine, I think - not sure why I missed that idea

Thanks all

@Silvia Yep, I Traced it after posting the answer. Infuriating and surely half as efficient as it could be.

I thought this was quite interesting news (about quantum stuff): newscientist.com/article/…. The related subject of communication faster than light is tantalizing.

@JacobAkkerboom It's extremely natural under Everett branching, which also makes it extremely natural why there's no "communication" - transfer of information - involved at all

you're simply determining where in phase space you are, by making a measurement

and the results of all your measurements constrain the possible universes you could be in

you can't be in an inconsistent universe, so things far away from you must have certain properties once you've made the measurement

(previously you had no opinion on which universes you might be in; then you made the measurement, whose result restricted which universes you might be in, and that means you know all measurements made of related quantities - elsewhere in the universe - must have certain outcomes)