If you've got an iPhone sporting the new 2.0 firmware, chances are you have Super Monkey Ball. (And if you haven't, what are you waiting for?) But there's more goodness to be culled from the iTunes app store besides playing games. There are plenty of cool apps out there, and some of the best ones don't cost a penny. After all, when you spend a big chunk of your disposable income on limited-edition video games, free and useful stuff is a godsend.