  We introduce the concept of a quantum walk with two particles and study it
for the case of a discrete time walk on a line. A quantum walk with more than
one particle may contain entanglement, thus offering a resource unavailable in
the classical scenario and which can present interesting advantages. In this
work, we show how the entanglement and the relative phase between the states
describing the coin degree of freedom of each particle will influence the
evolution of the quantum walk. In particular, the probability to find at least
one particle in a certain position after $N$ steps of the walk, as well as the
average distance between the two particles, can be larger or smaller than the
case of two unentangled particles, depending on the initial conditions we
choose. This resource can then be tuned according to our needs, in particular
to enhance a given application (algorithmic or other) based on a quantum walk.
Experimental implementations are briefly discussed.
