Looks like the EU's talks with Iran are failing in a big way, with the Islamic Republic threatening to stalk off and restart uranium enrichment a bit later this week. The article's a bit vague on what's killing them -- likely as not, that information simply isn't known -- but my guess is that there's simply not a lot the EU can offer Iran that they're not already giving them.
It's really a tough spot for those trying to stall Iran's weapon programs. Europe, theoretically, could apply serious sanctions and really pressure Iran into sitting at the table and hammering out a deal. But they won't. Worse, Iran's long-term trade prospects are brighter than their short-term ones, as their huge stores of natural gas (Iran and Russia have the most natural gas in the world, more than half the known total) are going to be in demand no matter how much of a pariah we judge them. China and India, frankly, don't much care how we feel towards Iran.
As far as the options go, this may mean that, pace Justin Logan, the only thing to do is learn to live with a nuclear Iran. Awhile back, I spoke to a disarmament expert who argued that there were two directions to go in when trying to control nukes -- nonproliferation and super-proliferation. The former no longer works well, as too many other countries have nukes for the states left behind to accept their lot in life. The latter's more interesting, it basically argues that we should help countries that're going nuclear do so in a safe way, which means building facilities that won't breach, security systems so the bomb can't be stolen, etc. That way, their weapons are less likely to disappear during times of unrest or revolution, and their relationship with America is less oppositional. Assuming that Iran is going to have one of these suckers sooner than later, helping them down that path -- and trying to improve our relationship with them as we do it -- may be our best bet.