  We discuss the ability of the SKA to observe QSO proper motions induced by
long-wavelength gravitational radiation. We find that the SKA, configured for
VLBI with multiple beams at high frequency (8 GHz), is sensitive to a
dimensionless characteristic strain of roughly $10^{-13}$, comparable to (and
with very different errors than) other methods in the 1/yr frequency band such
as pulsar timing.
