  We show how the momentum distribution of gaseous Bose--Einstein condensates
can be shaped by applying a sequence of standing-wave laser pulses. We present
a theory, whose validity for was demonstrated in an earlier experiment [L.\
Deng, et al., \prl {\bf 83}, 5407 (1999)], of the effect of a two-pulse
sequence on the condensate wavefunction in momentum space. We generalize the
previous result to the case of $N$ pulses of arbitrary intensity separated by
arbitrary intervals and show how these parameters can be engineered to produce
a desired final momentum distribution. We find that several momentum
distributions, important in atom-interferometry applications, can be engineered
with high fidelity with two or three pulses.
