So I have to live with 79€ annual fee. I see two possibilities how I can return this money: either I make the application non-free (e.g. $0.99 - the lowest rate available in the App Store) or I ask for donations and make it free. Please vote in the form at right what would be your preferable solution.
By the way, due to the App Store there probably will be a very few open source iPhone projects: first you have to pay for the development and second since applications are digitally signed and tracked every developer has a personal responsibility for his applications. He has to know the code as good as if he has written it himself. This eliminates the advantages of community-based development.