They've now added multi-colored neon lights to their massive "Bomb Me!" sign. From the Guardian:

Iran is secretly forging ties with al-Qaida elements and Sunni Arab militias in Iraq in preparation for a summer showdown with coalition forces intended to tip a wavering US Congress into voting for full military withdrawal, US officials say.

"Iran is fighting a proxy war in Iraq and it's a very dangerous course for them to be following. They are already committing daily acts of war against US and British forces," a senior US official in Baghdad warned. "They [Iran] are behind a lot of high-profile attacks meant to undermine US will and British will, such as the rocket attacks on Basra palace and the Green Zone [in Baghdad]. The attacks are directed by the Revolutionary Guard who are connected right to the top [of the Iranian government]."

The official said US commanders were bracing for a nationwide, Iranian-orchestrated summer offensive, linking al-Qaida and Sunni insurgents to Tehran's Shia militia allies, that Iran hoped would trigger a political mutiny in Washington and a US retreat. "We expect that al-Qaida and Iran will both attempt to increase the propaganda and increase the violence prior to Petraeus's report in September [when the US commander General David Petraeus will report to Congress on President George Bush's controversial, six-month security "surge" of 30,000 troop reinforcements]," the official said.

"Certainly it [the violence] is going to pick up from their side. There is significant latent capability in Iraq, especially Iranian-sponsored capability. They can turn it up whenever they want. You can see that from the pre-positioning that's been going on and the huge stockpiles of Iranian weapons that we've turned up in the last couple of months. The relationships between Iran and groups like al-Qaida are very fluid," the official said.