Time to share some very nice items with you :) Here you can see my first covers received from Iran, and franked with the WWF stamps I like so much :d Thank you very much Mehdi and Ali for your great help!
These are the covers from Mehdi (2x recto and verso):
These are the covers from Mehdi (2x recto and verso):
And these are the wonderful covers from Ali, including 2 first day covers (note that not one of the stamps on these - registered - covers has been cancelled... :s):
The animals pictured on the WWF stamps are the Asiatic cheetah (Acinonyx jubatus) and the Siberian crane (Grus leucogeranus)