  Experimental limits on the violation of four-dimensional Lorentz invariance
imply that noncommutativity among ordinary spacetime dimensions must be small.
Noncommutativity among extra, compactified spatial dimensions, however, is far
less constrained and may have discernable collider signatures. Here we study
the experimental consequences of noncommutative QED in six dimensions, with
noncommutativity restricted to a TeV-scale bulk. Assuming the orbifold T^2/Z_2,
we construct the effective four-dimensional theory and study interactions
unique to the noncommutative case. New vertices involving the Kaluza-Klein (KK)
excitations of the photon yield order 100% corrections to the pair production
and to the decays of some of the lighter modes. We show that these effects are
difficult to resolve at the LHC, but are likely within the reach of a future
Very Large Hadron Collider (VLHC).
