E.g.s of Large Sites?

For any small category, C, the presheaf category of functors from C^op to Set is a topos (and given a coverage on C restricting to those functors that are sheaves gives rise to a topos). Are there any known results of this type where C is not necessarily small? Thank you, Christopher Townsend, OU 20-Jun-2002 09:56:36 -0300,2065;000000000000-00000000