A couple pointers from Blog Iran:

First is an article serving as a reminder of some of Iran's doings, and the threat it poses through infiltration and terror activity to our troops and mission in Iraq:

Iran's Threat to Coalition Forces in Iraq

Then, we have two commentaries concerning a possible Congressional trip to Iran. First, Why Throw a Lifeline To a Sinking Regime? by Shaheen Fatemi and Badly Played, Old Chaps. Badly Played, by Pejman Yousefzadeh.

Message to Senator Specter: With all due respect Senator...Dude, they're laughing at you. They have no reason to actually give us anything. Their regime's on the brink. The people have lost faith with it. It's a failed government, yet the individuals in charge have no reason whatsoever to give up their power by soft choices. The only thing you can possibly do is prop them up, and give them ammunition to go to their dissidents, and those being tortured in their jails and say, "You see? They don't give a damn about you. They're on our side." Is that what you want to do? Natan Sharansky, writing of his time in the Russian Gulag, said that every time the West stood up to the regime, and forced it to be accountable, conditions and morale would improve for them. So stand up Senator!

"Now is a good time" to improve relations you say? To what end. This totalitarian regime is accountable to no one but themselves. Not to their people, not to you, and not to any agreement the clasp hands on. The more they lose legitimacy at home, the more they are simply individuals afloat without a life-line. Do not throw them that rope.