Ed Dreistadt sent me this link about using the iPhone as an in-vehicle interface for information like tire pressure and reminders about changing your oil. One key design feature of the iPhone is its interoperatbility--it has WiFi, so it can talk to any other WiFi device, it supports standard email and Web data, and it has an open software API so it is fast and easy to write custom applications for the iPhone. Small start up software shops (usually one or two people) are writing all kinds of software that use the iPhone to control other devices or as an interface to information in other places--because it's easy and fast. Other smartphones are finally starting to roll out that offer many of the same features, but the iPhone has an enormous head start.