  We study the effects of non-commutative QED (NCQED) in fermion pair
production, $\gamma + \gamma \to f + \bar{f}$ and Compton scattering, $e +
\gamma \to e + \gamma$. Non-commutative geometries appear naturally in the
context of string/M-theory and gives rise to 3- and 4-point photon vertices and
to momentum dependent phase factors in QED vertices which will have observable
effects in high energy collisions. We consider $e^+ e^-$ colliders with
energies appropriate to the TeV Linear Collider proposals and the multi-TeV
CLIC project operating in $\gamma \gamma$ and $e\gamma$ modes. Non-commutative
scales roughly equal to the center of mass energy of the $e^+e^-$ collider can
be probed, with the exact value depending on the model parameters and
experimental factors. However, we found that the Compton process is sensitive
to $\Lambda_{NC}$ values roughly twice as large as those accessible to the pair
production process.
