Do the following to get a visa quickly for Iran:
- Go to an Iranian embassy or consulate
- Fill in the forms, take passprt pictures etc.
- Submit the whole lot
- Call your embassy the same day in the country you're in
- Ask them to call your embassy in Tehran and request they contact central visa clearing admin in Tehran. They'll need your visa application number (either stamped or small sticker in your passport)
- They will call central admin and plead on your behalf.
- Central admin then Telexes (yes, it still exists) the consulate or embassy where you submitted.
- Confirm with your embassy they got the clearance
- Pick up the visa the NEXT DAY
I was told this process by the Iranian embassy in Damascus. Made the calls and in 2 hour I had approval. Picked up the thing next day. Got the full 30 days requested, no less.