Title for Roman Juszkiewicz: 

"Relative velocities of galaxies suggest a low-Omega Universe" 

Abstract (taken from astrp-ph/9912395):

We propose a simple and accurate method for computing analytically the
mass correlation function for cold dark matter and scale-free models
that fits N-body simulations over a range that extends from the linear
to the strongly non-linear regime. The method, based on the dynamical
evolution of the pair conservation equation, relies on a universal
relation between the pair-wise velocity and the smoothed correlation
function valid for high and low density models, as derived empirically
from N-body simulations. An intriguing alternative relation, based on
the stable-clustering hypothesis, predicts a power-law behavior of the
mass correlation function that disagrees with N-body simulations but
conforms well to the observed galaxy correlation function if negligible
bias is assumed. The method is a useful tool for rapidly exploring a
wide span of models and, at the same time, raises new questions about
large scale structure formation.