Not Since 1979
There is a report in the Washington Post that Iran has been trying to engage in direct talks with America regarding its nuclear program. Despite this unprecedented step, the Bush administration has decided that it wants Iran to talk to the three European countries that have been leading the nuclear talks.
I understand that Iran is doing this as a tactical move, and in this case as well as with North Korea, the administration doesn’t want to encourage the threat of building a nuclear weapon as a way to bilateral talks with the US. In this situation though, it seems like there is a lot we could gain by doing it, and very little to gain by remaining steadfast in our policy not to engage in direct talks. The Iranian government gets a lot of play among their people out of portraying America as a bully, and refusing direct talks only promotes this image.