Question: On the Australian embassy visa application there is a question about address and phone number of your contact in Iran. Does this mean the details of where you are staying? If so do you use the hotel you will be staying the longest at?
Answer: If you use an Iran-based travel agency, you can enter their number and details in the form or you can use the details of one of the hotels you are going to lodge in, for example your hotel in Tehran.
For Iran visa you should fill in the visa form on http://www.uppersia.com/Iran-travel-services/iran-visa.html, it takes about 10 working days to get your reference number and two working days to collect your visa at the embassy by direct referral or one working week by posting the docs to the embassy. You can pay the visa fee in cash in Iran.
Check the cheapest Iran tours at http://www.uppersia.com/Iran-tours