Sometimes you have so much power and you don't even know it. One in 3 of us carry smart phones with so much firepower that, used appropriately, they can lower your cost of living as you are out doing daily chores or buying stuff for fun.

There are so many apps for my Android phone that you can use to instantly comparison shop in the middle of a store! Two weeks ago, I was in a store with a friend looking at an electronics item. So I went on my phone and found the same item we were looking at $80 cheaper somewhere else. 80 bucks!

Then my executive radio producer Christa and I were in another electronics store looking at a Bluetooth keyboard attachment for her iPad that was being sold for $99.99. I went on my phone and looked and found it for $63.99 at a competitor. Now, the store where we were had a matching policy with competitors. So we went over to the counter with my phone, showed the salesperson that it was the identical item and bam! The price dropped from $100 to $64 just like that.

It's said that nobody uses the full capability of their smart phone and I really think that's true. Just remember, if you have a smart phone, you have in your hands the best comparison shopping tool ever. This is not just anecdotal, either. A recent article I saw in The Wall Street Journal corroborates that people are saving so much by using smart phones to comparison shop when they're in stores.

I have one app where I can take a picture of a barcode and the app searches the web for better prices on that same item. Google Mobile App lets me type in the name of an item and it will show me the nearest store with that item and the cheapest store with that item.

The biggest downside with these tools is that maybe you buy something that's a deal…but do you really need it?