The Federal Communications Commission's latest statistics show that Americans are sending more text messages than ever via their wireless devices. Text message traffic volume doubled between the second half of 2004 and 2005, from 24.7 billion to 48.7 billion messages.

At the same time the number of wireless phone customers in the United States leapt from 184.7 to 213 million, a national penetration rate of about 70 percent.

The data comes from the FCC's Eleventh Annual Report to Congress on the state of competition in the Commercial Mobile Radio Services (CMRS) industry, released this week.

At the same time, the cost of cell phone service dropped. The per-minute price of wireless phone service fell 22 percent last year, from nine cents a minute in 2004 to seven cents in 2005.

"This year’s Competition Report demonstrates that the competitive marketplace for wireless services is continuing to bring consumers more choice, better services, and lower prices," FCC Chair Kevin Martin said in a statement.

The top mobile telephone operators by subscriber remained more-or-less static during this period. Cingular and Verizon Wireless ranked number one and two in 2004 and 2005, both with over 50 million subscribers. Sprint Nextel came in third with over 44 million subscribers in 2005. T-Mobile remains in fourth place with over 21 million customers.

But the report also disclosed that the U.S. penetration rate of mobile wireless technology continues to lag behind Western Europe—even France, with its rate of 79 percent.

"Thus, as in previous years, U.S. mobile penetration at the end of 2005, at approximately 70 percent, was lower than the lowest mobile penetration rate in Western Europe," the report conceded. Japan's penetration is slightly higher than the U.S., at 74 percent.