  We describe a scheme to demonstrate the nonlocal properties of a single
particle by showing a violation of Bell's inequality. The scheme is
experimentally achievable as the only inputs are number states and mixed
states, which serve as references to `keep track of the experiment'. These
reference states are created completely independently of one another and
correlated only after all the measurement results have been recorded. This
means that any observed nonlocality must solely be due to the single particle
state. All the techniques used are equally applicable to massive particles as
to photons and as such this scheme could be used to show the nonlocality of
atoms.
