If the speculations going around are going to swear by, then Apple is in the process of making some very interesting changes to its iPod nano. The iPhone maker has filed a patent which talks at length about the iPod being enabled with the ability to change its screensavers, as per the surroundings.
A screensaver for every surrounding..
It’s no magic, even if it seems to be one! The concept has been modeled on the array of sensors on the iPod Nano – camera, thermometer, microphone and accelerometer, being the ones. The sensors promptly deliver information from the surroundings to the iPod, and the iPod then, based on the inputs provided will pick an apt screensaver. This goes to say that the iPod will have a variety of screensavers to go with varying surroundings. For example, if the weather outside is cloudy, you'll have a screensaver with rain droplets on them.
Having said that, there has not been any confirmation, as such on the whole topic and it stands speculative as of today.