I was planning on doing something like this myself but The Unofficial Apple Weblog has beaten me to the punch. They have created a useful summary of Apple iPhone 3G pricing and service contracts. It covers all countries that will release the iPhone 3G on July 11th and France which will release it on July 17th.
TUAW will keep updating the document as new plans and pricing get announced.
At a glance you can see how your country fares against others. For example, no country aside from Canada is requiring a three-year service contract (no bitterness here!).