From what I can tell, pulsars emit light in beams from the poles of the pulsar. Would it be possible to construct something to get energy from a pulsar's beams of radiation? Or is this as idiotic of an idea as... erm, an idiotic idea. (I am not good at metaphors.) Would this be easier than building a Dyson sphere?
If your civilization has reached the point where it can build Dyson spheres, harvesting a pulsar is actually a good idea. However, a special consideration must be taken.
Most stars produce energy through nuclear fusion at the core. Pulsars, on the other hand, are dead at the core. Their energy output comes from stored thermal energy, but mostly from a comparatively strong magnetic field. The field accelerates protons and electrons at the poles into relativistic speeds, thus generating the beams for which pulsars are famous.
So you could, in theory, build a dyson ring or sphere (since they do radiate in all directions, just not as strongly as through the poles) around the pulsar and it would work just fine. However, you could also tap the source of the pulsar directly, and that should be more efficient - if only because there is one less energy conversion in the way.
What you need is a toroidal coil of dysonic proportions. This is a toroidal coil:
Have one of these circling around the pulsar, preferably slightlgy misaligned with the pulsar's rotation plane. With this power source your amps' dials will be able to go way past eleven!
P.s.: All a regular dyson sphere does is passively collecting a stars' energy, without actually draining it. This dyson coil setup will however drain the pulsar and reduce its lifetime.