Update: Go to my list of iOS 8 apps, from October 2014.
[See the new list of iPhone applications I actually still use in this post, from September 2009.]
I am surprised by how well this list of iPhone apps I actually use has held up over the past few months. Most of the apps I've added in recent months have been games, none of them particularly amazing, although my daughter swears by one, Jelly Car. I have to admit, it is fun.
The only significant new application I've added is the Amazon Kindle for iPhone. It has quickly become one of my favorites. I actually find reading on it preferable to the clunky Kindle 1 in some ways. (I read most of this book on the iPhone.)
The application is free, but of course you need to own an Amazon Kindle and download some books. Kindle newspaper and magazine subscriptions don’t work, nor can you read documents you have sent to yourself or ebooks from sources other than Amazon (the original Kindle allows this). Unfortunately, Amazon and publishers have recently raised the cost of new Kindle books. The page-turning is easier than the Kindle 1, and of course the phone has a backlight, while the Kindle uses e-ink that is supposedly easier on the eyes but requires outside light. The coolest feature is the Whisper Sync: You are taken to the most recent page you read, whether on the phone or the Kindle.