This is a guest blog entry from Karin Gerber.

In this day and age we don’t use our mobile smartphones for just talking and text messaging anymore.  Did you know you can now make purchases with it as well?

It wasn’t that long ago when shopping transactions were done by either cash, check, or credit card.  People then started shopping and buying items online from their computers.  Nowadays, it seems we are moving away from even using computers to using portable devices and smartphones to help us in our everyday lives.

Starbucks introduced a mobile application for the iPhone, iPod Touch, and select BlackBerry smartphones where customers can pay for their coffee right from their mobile device.

Starbucks’ pay-by-phone smartphone application acts as a virtual Starbucks Card that you can reload using your credit card (iOS users can also use PayPal). The application also lets you check your card balance, monitor your Starbucks reward points and see nearby Starbucks locations on a map or list… To pay with your device, you hold your handset up to a scanner at the Starbucks register that reads a bar code displayed on your screen. The app maintains a running balance of your card payments so you’ll know if you’ve run out of money before your next caffeine fix.  (via PCWorld)

What about security with the Starbucks mobile app?  You can choose if you want the app to store your credit card information which makes it easier to reload your Starbucks card.  You can even add a passcode to the application as an added precaution.  However, you can always go to to reload your card if you’d rather not save your payment information on your device.  Another possible option is to buy a new Starbucks Card in a store and then add the card number to your account.

If Starbucks already has the technology to do this so can the many other retail merchants out there.  I can see smartphone applications making the use of credit cards less apropos at some point in the future, just like what happened with Compact Discs when MP3s made it to the mainstream.  CDs aren’t obsolete yet but they’re not as prevalent as they were years ago.  I can see the same happening to the use of credit cards.  It’s amazing to think what our smartphones are capable of.