Last night I was at Wal-mart and I used my smartphone for some price matches.
Since Wal-Mart Price matches competitors prices I used ShopSavvy for Android
HERE, iTunes
HERE or Windows phone
HERE. The app is 100% free and worth having on your phone.
I scanned the barcode using the app and it told me the cheapest price in my area.
At the register I told the cashier I had price matches and I saved $12 on a $40 tab making my final bill only $28! My smartphone pays for itself!