  We review here recent numerical results concerning the acceleration and
collimation of relativistic outflows from neutron stars, and we discuss their
implications for models of magnetars in their hypothesized initial high
rotation states. New results with different injection conditions and extending
to much larger distance from the central star are also presented and discussed,
showing that, only in the case of weakly magnetized winds, collimated outflows
are indeed possible. We finally comment on the possibility that newly born
magnetars might trigger GRBs, and we show that numerical results do not support
such hypothesis.
