This is our third installment in a series of posts on fitness gadgets that will motivate you to stay fit.  Don’t forget to read the first and second posts after you read this one.

A smart phone is a fitness gadget you may already own.  There are a wide variety of iPhone and Android apps that will help you keep track of what you eat and how many calories you’ve consumed.  Many people are using smart phone apps like RunKeeper to track their workouts while listening to their favorite tunes via music apps like Pandora Radio.   There are also apps that can serve as personal trainers.   You can also use your phone as an e-book reader to catch up on your reading as you workout.

For more details about fitness apps for smart phones, see this CNET review of the Top iPhone Fitness Apps.  For Android Fitness Apps, see this Lifehacker review.

For gadget lovers who live in colder climates, the question of how to use a touchscreen with freezing fingers is relevant this time of year.  Most touchscreen devices, including the iPhone, iPod Touch and Droid, require charges from the fingertips in order to work correctly.  Touch the screen with a glove covering the fingers just won’t work.    

One of the top makers of touchscreen-friendly gloves is Freehands.  Their gloves feature removable flaps for the index finger and thumb and come in fleece, cashmere or wool.  They also make touchscreen-friendly sports gloves.  Prices range from $16 to $45.

To see a complete lineup of gloves that are well-suited for touchscreens, see this Mashable review.

Turn your iPhone into your personal car mechanic with Kiwi’s Car Diagnostic Kit.  After you’ve plugged the KiWi wireless device into your car’s diagnostic system (through the OBDII port beneath the steering wheeI) , a suite of downloadable iPhone apps will monitor problems and report on torque, horsepower and other engine information.

That flashing dashboard light doesn’t have to be a mystery – let the Kiwi Wifi tell you what it means.  Find out more on the PLX Devices website.  See it in action on a BMW 135 in this YouTube video:

With a price tag of about $3 million USD, the iPhone 3GS Supreme is offiically the most expensive iPhone in the world. Luxury designer Stuart Hughes created this custom-designed solid gold model and embellished it with dozens of diamonds, including a 7 carate single cut diamond for the navigation button. This YouTube video demonstrates the iPhone 3GS Supreme:

You can see some of the other luxury items that have been customized by Hughes on the Stuart Hughes website.

Apple’s new iPad supports the touch screen technology that has made the iTouch and iPhone so popular. We doubt if Apple tested the iPad on any non-human users, but here’s a YouTube video that shows the appeal of the iPad for a cat named Iggy.

Do you think its claws scratched the screen?

The Vue is a personal video network that provides wireless access to video camera output. Small Vue cameras can be easily installed in your home or business using a patented peel-and -tick magnet system. The output from the camera can be remotely viewed from any web browser or iPhone.

Avaak provides each user with a secure account at VueZone.com where video clips can be stored and viewed later. Videos can also be uploaded to Flickr and YouTube. Although Avaak plays up the fun aspects of sharing Vue videos, the most obvious use of this system is as a personal security system and for keeping tabs on what’s going on when you’re not there. The basic system with 2 cameras sells for $299 on Amazon. Additional cameras cost $99 each.