  We report measurements of current noise in single- and multi-layer graphene
devices. In four single-layer devices, including a p-n junction, the Fano
factor remains constant to within +/-10% upon varying carrier type and density,
and averages between 0.35 and 0.38. The Fano factor in a multi-layer device is
found to decrease from a maximal value of 0.33 at the charge-neutrality point
to 0.25 at high carrier density. These results are compared to theoretical
predictions for shot noise in ballistic and disordered graphene.
