  We study the dynamics of 3 point-vortices on the plane for a fluid governed
by Euler's equations, concentrating on the case when the moment of inertia is
zero. We prove that the only motions that lead to total collisions are
self-similar and that there are no binary collisions. Also, we give a
regularization of the reduced system around collinear configurations (excluding
binary collisions) which smoothes out the dynamics.
