This puzzle is a quantum circuit. The measurements will yield one of the following eight states, each with equal probability:
|000> x |01100>, |001> x |01111>, |010> x |01100>, |011> x |01100>, |100> x |11001>, |101> x |00111>, |110> x |00001>, |111> x |00111>.
The first three qubits form the numbers 0 through 7 in binary once each. Using these as an ordering on the states and converting the last five qubits to letters using the code A = |00001>, etc., we obtain the answer LOLLYGAG.
2006 MIT Mystery Hunt