Lose horn, save rhino: iLIVE
It seems to me it is much easier to poach rhino horn with the support of the local population than without it, and that, therefore, we should allow rhino horn to be legally harvested ("Poaching season is near", yesterday).
This would be on condition the permit-holder devotes a percentage of profits to uplifting the local populace, thereby giving locals a powerful incentive to side with conservationists against poachers. Apparently, the horn can be removed without causing too much trauma and grows back fairly quickly, yielding a steady income.
In an environment devoid of apex predators like lions, the loss of the horn is probably not worth getting excited about.