  Hawking radiation can usefully be viewed as a semi-classical tunneling
process that originates at the black hole horizon. The same basic premise
should apply to de Sitter background radiation, with the cosmological horizon
of de Sitter space now playing the featured role. In fact, a recent work
[hep-th/0204107] has gone a long way to verifying the validity of this de
Sitter-tunneling picture. In the current paper, we extend these prior
considerations to arbitrary-dimensional de Sitter space, as well as
Schwarzschild-de Sitter spacetimes. It is shown that the tunneling formalism
naturally censors against any black hole with a mass in excess of the Nariai
value; thus enforcing a ``third law'' of Schwarzschild-de Sitter
thermodynamics. We also provide commentary on the dS/CFT correspondence in the
context of this tunneling framework.
