7 clever uses for ordinary smartphone features

You've heard the old saying, "Familiarity breeds contempt." When it comes to technology, I'm not sure if contempt is the right word. Perhaps it's better to say, "Familiarity breeds indifference." Well, it's time to bring back some of the wonder. I've rounded up seven amazing things you didn't know your smartphone could do.

1. Rewind the past

"Did I hear that right?" We've all had moments where we're sure we misheard something someone said. Or someone said something hilarious and we wish we had a recording.

Well, now you can pull audio from the past. No, I'm not saying your phone can time travel - yet.

Heard for iPhone is always recording using your smartphone's microphone. At any time, you can save audio from up to 5 minutes in the past.

Don't miss your baby's first words or the name of that important client again.

2. Help you sleep better

Many people blame technology for their lack of sleep. Staring at a screen confuses your brain about the time of day. Your phone buzzes from incoming text messages and wakes you up throughout the night.

Well, technology can be a solution as well. Give Sleep Time for iPhone and Android a shot.

You start by placing it on your mattress before you go to bed. The phone's accelerometer detects your movements during the night and figures out your sleep pattern.

The app's alarm gently wakes you up during the lightest part of your sleep cycle. You can avoid that groggy feeling that makes you want to hit the snooze button.

3. Make you aware of your surroundings

Listening to music or watching a movie on your smartphone is a great way to pass the time. It can make your morning walk or a bus ride fly by.

The downside is that many earphones block out the surrounding noise. That's great if you want to tune out the world. It's not so great if a car is honking at you or the driver announces your stop.

Awareness for Android and iPhone fixes that problem. It uses your smartphone's microphone to keep track of noise around you. Any sounds louder than regular background noise gets sent to your headphones.

You can hear a car honk, a bus stop announcement or your friend talking. And you won't miss a second of your music or video.

4. Help you measure up

As my Dad always used to say, "Measure twice, cut once." Even if you're not cutting anything, measuring can prevent costly mistakes.

But you don't have to reach for a ruler or tape measure. Android users can fire up Advanced Ruler Pro and iPhone users can grab Visual Measure.

Just take a picture of an object or room and then follow the directions. The app can figure out the dimensions for you. From a chair to a mansion, you can measure virtually anything.

iPhone users also have the amazing Acoustic Ruler Pro. This uses sound reflection to measure distances. It's similar to the way bats detect bugs and obstacles.

There are two modes. If you have two iPhones, you can measure distances up to 82 feet. With one iPhone, you can measure distances just under 4 feet.

5. Give you heart

Smartphones and tablets are on their way to becoming indispensible medical gadgets. They've already been wired with sensors to detect certain blood chemicals. MIT created an add-on, NETRA, which turns any smartphone into a portable eye tester. The list goes on.

Most of these advances are years away from being commercial or require add-ons. However, some people are doing interesting things with the smartphones they already have.

Instant Heart Rate for iPhone and Android uses the phone's camera to figure out your heart rate. It detects the light passing through your finger and how it changes as your heart beats.

You can keep a log of your heart rate to track it over time.

6. Help you prove your metal

There are plenty of valuable items that people drop every day. A simple metal detector is all you need to find them and make some extra money.

Don't have a metal detector? Don't need one. Metal detector apps for Android and iPhone have you covered.

No, I'm not joking. Smartphones contain a compass for navigation. It's not difficult to tweak it to detect nearby metal objects.

You will need to find a comfortable way to hold your phone near the ground, however. Walking around bent over just looks odd!

7. Prevent a lapse in attention

Time-lapse videos are amazing. You can watch natural phenomena unfold that would take too long with the unaided eye.

Time-lapse pros use expensive, high-tech equipment to get their shots. If you want to try your hand at it, however, it only takes a few bucks.

Your smartphone can make time-lapse movies no problem. Just grab TimeLapse for iPhone or Lapse It for Android.

You can set how frequently the camera snaps a picture. Then the app will put the images together in a movie file. You just need to tap a button.

Well, you also need to figure out a good way to keep your phone pointed where you want. There are plenty of low-cost tripod hacks people have come up with online.

If you want a premade solution, you can grab a smartphone tripod. Look at the GripTight GorillaPod from Joby ($30) or the Sony SPA-MK11 ($30).

Kim Komando hosts the nation's largest talk radio show about consumer electronics, computers and the Internet. To get the podcast, watch the show or find the station nearest you, visit: www.komando.com/listen. To subscribe to Kim's free email newsletters, sign-up at: www.komando.com/newsletters.