Go on localbitcoins.com and type in 'Tehran'. There's also a very popular mailing list/forums for trading in Farsi I have to dig up the link when I leave my office.

Argentina has also embraced bitcoins en masse considering it's now illegal to transfer any money out of the country, and no Argentinian trusts their bank to not steal all their deposits. On payday in Argentina you see huge lines of people at the ATMs withdrawing everything they own to keep under a mattress, or smuggle to Uruguay to deposit in a stable bank.