Updated

Smartphone plan prices just hit a new low. Republic Wireless, the company behind the highly anticipated $19 per month unlimited smartphone plan, is now shipping phones nationwide. This no-contract plan keeps prices down by utilizing both Wi-Fi and 3G to limit the amount of voice, text and data that's transferred through cellular networks.

"We saw Wi-Fi becoming ubiquitous and cheap, while cellular spectrum has become increasingly expensive” said David Morken, CEO of Republic Wireless. “So we set out to invert the status quo, by routing as much as possible – voice, text, and of course data, over Wi-Fi whenever possible."

This technology will only improve over time as the number of public Wi-Fi hot spots increases at the projected growth rate of 350 percent between 2011 and 2015, according to the Wireless Broadband Alliance. Additionally, more and more homes and offices are becoming equipped with wireless Internet, making it increasingly easy to avoid using cellular networks.

The $19 per month plan, which includes unlimited voice, text and data, is currently the cheapest option in the U.S. A similar plan on Virgin Mobile costs just $35 per month and on Verizon Wireless, which requires a 2-year contract, prices are $90 per month for just 1GB of data and unlimited voice and text.

Unfortunately, the plan is only available for the Motorola DEFY XT smartphone, available for purchase through Republic Wireless' website. There's no word if the plan will one day be available for other smartphone models, but the company says it is optimistic about the possibility.