I have emailed with Vodafone to ask about their coverage in Iran; for my Blackberry.
From their answer, I gather that I may be able to connect with my Kindle to Amazon, or check my mail; as my (European version of the)Kindle also has a Vodafonecard.
Vodaphone:
"Thanks to the SIM card, which we have been delivering standard few years, your device will automatically choose for Vodafone (partner) network abroad. The networks in Iran, where Vodafone has a roaming agreement with: MCI over the GPRS network and Thuraya. "