Carriers today launched a joint initiative aimed at replacing your debit card -- with your smartphone. Today AT&T, Verizon Wireless and T-Mobile launched Isis in the trial markets of Salt Lake City, Utah and Austin, Texas. Isis uses near field communication (NFC) for payments, storing your bank information securely on a new SIM card you'll need to pick up from your carrier. The application can be downloaded from Google Play for your respective carrier, though current phone support is limited.

On T-Mobile, only the Samsung Galaxy S III , Galaxy S Relay 4G, and Galaxy S II can currently use Isis, with the HTC Amaze 4G and Samsung Galaxy Note II added before year's end. Rooted phones won't work with the new service.

On Verizon Wireless, Isis only works on the HTC Droid Incredible 4G LTE, with support for Droid Razr HD and Droid Razr Maxx HD coming within weeks.

If you're on AT&T, the service is currently only available for the Samsung Exhilarate, the Samsung Galaxy S III, the LG Escape, the HTC One X, and the Samsung Galaxy Rugby Pro.

The service is also fractured in that, while Google Wallet works as a uniform payment system (think Paypal), Isis really only works in stores that are clearly labeled as "Isis ready." It means adding yet another payment service into your stable of options, though it seems obvious that these services will all see integration eventually. Ideally, users will be able to store discount offers and use them during the final transaction. If you're curious, the companies are offering a video highlighting how the system works.

Obviously security concerns are something to watch, and many are skeptical about handing over banking data to companies that don't have much regard for privacy law when it comes to the myriad of data they already collect. Isis is expected to expand beyond the first two trial markets by early next year.