According to Palm, the device can be used with any wireless carrier that supports the quad-band GSM wireless standard, which operates at 850/900/1800/1900 MHz.

Palm said it has sold more than 1 million Centro units since its launch in September and expects to hit the 2 million mark in the very near future.

The Centro is Palm's attempt to not only hit the business users accustomed to its devices, but to target consumers and first-time smartphone users and woo them away from the likes of the iPhone or Research In Motion's growing line of BlackBerry devices aimed outside the corporate world, such as the BlackBerry Pearl, the BlackBerry Curve and the up-and-coming BlackBerry Bold.

One of the major selling points for the Centro has been its affordability. AT&T, Sprint and, most recently, Verizon Wireless offer the Centro for a hair less than $100. Palm said the unlocked version, however, will cost $299— plus free shipping—and can be used with any wireless carrier's network, as long as GSM is in the cards. And while the unlocked Centro doesn't offer 3G support, it supports 2.5G on the EDGE network. Currently, a host of carriers use GSM, such as major players AT&T and T-Mobile, along with a handful of smaller, regional carriers. GSM is also widely used in other parts of the world, meaning the Centro can be carried globally.

The unlocked Centro, like the Centros available from the carriers, weighs in at 4.4 ounces and measures 4.2 x 2.1 x 0.73 inches. It features a 320 x 320-pixel touch screen and a full QWERTY keypad. In addition, the Centro features Bluetooth support, a microSD slot for up to 4 GB of expanded memory and a 1.3-megapixel camera with two times zoom and video capture.

Palm is offering the unlocked Centro, which is available in white with a grey number pad and accents, on its Web site.