Energy...

Cell phones can use a lot of energy to run applications like Bluetooth and Wi-Fi. But they don't have to. A new app for Nokia Series 60 phones can help control energy usage, making them more efficient and reducing your carbon footprint.

The app, called GreenPhone, monitors your phone usage and lets you know when you can turn off features that you're not using, but which are sucking power out of your battery. These include the backlight, Bluetooth and WLAN features.

GreenPhone also helps inform you when your phone is done charging so you can unplug it, since mobile-device chargers tend to keep using electricity even when they are done charging whatever they're connected to.

The program doesn't do all of this by itself. You customize the amount of time you want the backlight to stay active, and it sends you text messages to remind you to turn off your Bluetooth or wireless, or to unplug your charger. (Don't worry. Since the text messages originate on your phone, you don't incur any fees.)

GreenPhone was one of the winners of Nokia's recent Calling All Innovators competition. It's available for download for $15 here.You can watch a YouTube video about it here.