Do Christians have the authority to forgive sin?

Catholic doctrines of Penance teach that if a priest forgives the sin of a parishioner, then that sin is forgiven by God as well- the sacrament of Penance is _effective_, and not just ceremonial. Likewise, the doctrines on excommunication from the church say that if a person is damned by the church, the anathema is _effective_. A common phrase in the Gopels (cf. John 20, Mark 18) is _What is loosed is loosed, and what is bound is bound_. What denominations or Christian groups other than the Roman Catholic Church teach specifically that a Christian can or cannot forgive the sins of another person? If a particular denomination teaches that they _can_ do, do the doctrines of the denomination distinguish between the members of the Church that are able to perform this ministry and those that are not?