Today Apple showed off applications that are being made with the new developer sdk for the iPhone. All iPhone customers will be receiving a free update in June to be able to download the applications. Until June, the program is in beta.
Games will also be coming to the iPhone. Full versions of both Super Monkey Ball and Spore were shown and playable on the iPhone. EA states that the full version of Spore will be released for the iPhone.
Just another reason to save up to buy an iPhone.