  We consider the constrained zero modes found in the application of discrete
light-cone quantization (DLCQ) to the nonperturbative solution of quantum field
theories. These modes are usually neglected for simplicity, but we show that
their inclusion can be relatively straightforward, and, what is more, that they
are useful for nonperturbative calculations of field-theoretic spectra. In
particular, inclusion of zero modes improves the convergence of the numerical
calculation and makes possible the direct calculation of vacuum expectation
values, even when the zero modes are determined dynamically. We also comment on
zero-mode contributions not included by DLCQ, namely zero-mode loops.
