  We propose a physical mechanism for tuning the atom-atom interaction strength
at ultra-low temperatures. In the presence of a dc electric field the
interatomic potential is changed due to the effective dipole-dipole interaction
between the polarized atoms. Detailed multi-channel scattering calculations
reveal features never before discussed for ultra-cold atomic collisions. We
demonstrate that optimal control of the effective atom-atom interactions can be
achieved under reasonable laboratory conditions. Implications of this research
on the physics of atomic Bose-Einstein condensation (BEC) and on the pursuit
for atomic degenerate fermion gases will be discussed.
