As expected, Isis — the mobile payments solution backed by several major US carriers — launched today in Austin, Texas and Salt Lake City, Utah. After a handful of delays, the service is now available to AT&T, T-Mobile, and Verizon Wireless subscribers in both test markets. Starting today customers with an Isis-enabled handset (Verizon, T-Mobile) can head to their nearest carrier for the specialized, secured SIM card required to make payments on the go. The list of supported devices is fairly small at the moment but Isis expects 20 handsets to ship before year's end.

You'll also need to download a standalone Isis app specific to your carrier from Google Play before getting started; we've linked to all three of them below. If you don't have an eligible American Express, Capital One, or Chase card, there's an option to add funds to a prepaid Isis Cash card — much like the approach Google Wallet once took. Sadly for everyone outside these cities eager to give Isis a test run, the company isn't yet saying when it plans to expand further.