  We are interested in the numerical solution of linear hyperbolic problems
using continuous finite elements of arbitrary order. It is well known that this
kind of methods, once the weak formulation has been written, leads to a system
of ordinary differential equations in $\R^N$, where $N$ is the number of
degrees of freedom. The solution of the resulting ODE system involves the
inversion of a sparse mass matrix that is not block diagonal. Here we show how
to avoid this step, and what are the consequences of the choice of the finite
element space. Numerical examples show the correctness of our approach.
