In case you've been living in a cave, with the latest firmware release for the iPhone (1.1.3) you can now customize the arrangement of the icons on your home page. To do this, place your finger on any icon and leave it there. After a second or so, all of the icons will begin shaking in place. Once the icons are all shaking, you can drag and drop the icons into new locations. You can also drag them off the screen to create multiple tabbed home pages. Once you are happy with how you icons are arranged, hit the Home button to get out of this editing mode.