  We find further evidence for the conjecture relating large N Chern-Simons
theory on S^3 with topological string on the resolved conifold geometry by
showing that the Wilson loop observable of a simple knot on S^3 (for any
representation) agrees to all orders in N with the corresponding quantity on
the topological string side. For a general knot, we find a reformulation of the
knot invariant in terms of new integral invariants, which capture the spectrum
(and spin) of M2 branes ending on M5 branes embedded in the resolved conifold
geometry. We also find an intriguing link between knot invariants and
superpotential terms generated by worldsheet instantons in N=1 supersymmetric
theories in 4 dimensions.
