I've had my iPhone for about a year now, and it's just as indispensable as my Palm used to be. Here are my favorite apps for the iPhone.
OneBusAway. Based on the real-time location information from most bus lines (or train or ferry), OneBusAway tells me how long until my bus arrives. Then I can decide if I have time for breakfast at home or if I have to dash out the door. It does break down in very-slow-bus scenarios, such as snow or Sounders events. (Useful mainly in Puget Sound, but available for a variety of devices.) It's free!
NASA. NASA's app is a great way to keep track of our space-faring activities. You can track launches, watch videos, and even look at daily pictures such as the APOD. The NASA app makes it super easy to save the pictures for use as lock screen / wallpaper images. (Available for iPhone and Android. Also, free.)
2Do. Yes, it's another to-do list application. But it's got a huge feature set. As a Palm devotee, I had very high demands for my to-list application, and despaired of finding one that met my needs. 2Do does everything that I need it to, and still has features left over.
There are a few "natural laws" of riding public transit that I have noticed over several years of bus ridership.
Slightly early buses tend to become very early buses as they progress along their route. As passengers miss the slightly early bus, the bus saves time and becomes even earlier. The same is also true for a very slightly late bus; it will have to pick up more passengers, and become even later.
If one bus is early, the next one will probably be late. That second bus must to pick up the passengers who missed the first bus.
If one bus is late, the next one will probably be early. The first bus has picked up some passengers who otherwise would have had to wait for that second bus.
Buses tend to be more crowded, and hence later, during inclement weather. Some walkers will ride the bus if it's raining, and many drivers will ride during snow or ice.
Most of the time, a bus will be at the front of a line of traffic. Stops along its route will cause the bus to be the slowest traveler in its traffic lane.