Shane Bauer and Josh Fattal. You know them better as "the hikers". Still in Iran after two years.
What the movement for their release is currently trying to do right now is call the Interests Section of the Islamic Republic of Iran- that's in Washington- en masse and kindly- KINDLY- ask for their release. The hope is that the sheer volume of calls on their behalf might be able to force a bit of progress.
If you do call, you're requested to be nice. That can't be stressed enough. Don't go yelling at them. Yelling may only make matters worse.
The number is (202) 965-4990. That number specifically. The requested details to hit upon in the call are here. They may ask for you to follow up with an e-mail; the address for that is firstname.lastname@example.org. If they tell you they're not a political office- and they may- just tell them to pass the message along to one.