Portable GPS device maker Garmin recently said its much-delayed nuvifone line, which was first announced in January of 2008, will be launched in the USA before year's end. A full advertising campaign will accompany the device. In a recent conference call with analysts, Garmin revealed the device is undergoing the final stages of testing with US carriers, though stopped short of naming the carriers.

AT&T has been figured as the most likely due to its support for GSM calls and HSPA-based 3G, both of which which the nuvifone needs to support elsewhere.

The company recently began shipping its first nuvifone, the Linux-based G60, to Asia. Its true smartphone, the Windows Mobile-based M20, will ship in Asia this August and isn't due to reach US shores. [via TWICE]