One of the iPhone’s neat features is it ability to automatically reorient the screen from portrait to landscape when you turn the phone to the side. This feature is the kind of thing that gets first-time users really excited — it’s like the iPhone knows what you want it to do.

And not only that, the feature lets you do things that you can’t do any other way. Using Coverflow in iPod and watching videos can only be done when the iPhone is in landscape mode, for instance.

But there’s a problem. The reorientation feature doesn’t seem to work as well as it should.

The reorientation feature is triggered by an accelerometer, a sensor that knows when you’ve moving the iPhone quickly. When the sensor sees you doing this, it changes the screen orientation. But I’m finding that it doesn’t do it as consistently as it could. Sometimes I’ll slowly turn the iPhone to enable Coverflow in the iPod and nothing happens. Only when I turn it back to portrait does Coverflow show up, and then only for a second before the regular interface reappears.

Reorienting the screen in Safari is a little better, with the program being more responsive. Still, the iPhone isn’t as responsive to these changes as it could be. Friends and colleagues who play with my iPhone for the first time can rarely make the screen reorientation feature work without some coaching from me.

It’s a big problem. The iPhone’s screen orientation changes just fine when it needs to. It’s just another feature that could be improved in future iPhone models.