Anyone who is not a stranger to this blog knows that I don't have an iPhone and my preferred geocaching tool is my trusty Garmin GPSmap 60CSx device. Even so, I thought I would share this interesting article I ran across for any iPhone geocachers out there. Even though this post from iPhoneNess is called, 10 Awesome iPhone Apps For Running, there are some interesting features in many of these apps that should appeal to cachers.
For example, the second one on the list, called "iSmoothRun" allows you to export your data in GPX, TCX, KML, or CSV format. Presumably this data output includes the recorded lat/long coordinates of your outing and therefore should look like a typical GPS track log file, which can then be opened in any GPS mapping application such as Basecamp, Everytrail, or even Google Earth.
You'll also notice that many apps on the list are described as, "excellent for running, cycling and hiking". And as we all know, any tool that is good for hiking is good for geocaching. This includes the suite of apps by the company that makes, "MapMyRun". However, I would suggest for caching that you try their "MapMyHike" app instead. With this tool, you can track and log your hikes, complete with elevation data. It also integrates with popular social networking apps like facebook and twitter.
Hopefully you'll find one or two apps on this list worth your while.