  We introduce a scheme for linear optics quantum computation, that makes no
use of teleported gates, and requires stable interferometry over only the
coherence length of the photons. We achieve a much greater degree of efficiency
and a simpler implementation than previous proposals. We follow the "cluster
state" measurement based quantum computational approach, and show how cluster
states may be efficiently generated from pairs of maximally polarization
entangled photons using linear optical elements. We demonstrate the
universality and usefulness of generic parity measurements, as well as
introducing the use of redundant encoding of qubits to enable utilization of
destructive measurements - both features of use in a more general context.
