  A future linear e+e- collider with a clean environment, tunable collision
energy, high luminosity, polarized incoming beams, and additional e-e-, e-gamma
and gamma-gamma modes, will offer precision tools to explore new physics. Here
we summarize three papers submitted to the ICHEP04 conference in which
polarized e+e- and gamma-gamma beams are exploited to search for CP violation,
and universal extra dimensions (UED).
