Google has begun testing text ads on cell phones, offering publishers a way to make money off of their mobile sites, according to Business 2.0 blog The Utility Belt.

The blog also offered up some details: "The ads contain two lines of text, with 12 or 18 characters per line, depending on the language. Advertisers have the option to let people call their business directly from the ad. Advertisers pay only when someone clicks on the ad, or initiates a call from the ad."

This sounds reasonable and fairly unobtrusive compared with some other, less welcome kinds of mobile ads. Given Google's success on the desktop (to put it mildly), this move into the mobile realm could be the jump start for a much broader range of cellphone content.

Google testing AdSense for cell phones [The Utility Belt]