Smartphones are rapidly gaining popularity in Brazil as recent price reductions have made these devices more accessible to people of all economic levels according to new research from The Nielsen Company.

In many developing markets, inexpensive and available mobile phones serve as a substitute pathway to the Internet. Rapid mobile phone adoption presents “reverse innovation” opportunities for clever marketers who leverage the trend.

Widespread ownership of mobiles is only a fairly recent development in China, but consumers there have fully embraced the technology and in some ways are using it more robustly than their American and European counterparts.

In the U.S., young people’s media usage is markedly different from that of older generations but is likely to converge with their elders as they themselves grow older, according to Nielsen SVP of Consumer Insights Dounia Turrill at today’s Consumer 360 conference in Las Vegas.

In a demographic view of social networking activity on mobile devices, women were found do use their phones to “tweet” and “friend” 10% more than men.

Trends in 2009 include a rise in households that have “cut the cord” by trading their traditional landlines for wireless cellular services and an increase in mobile media device usage among a diverse set of households.

The launch of the Droid by Motorola–which runs Google’s Android 2.0 operating system–is the latest smartphone to be tagged “a game changer,” and “the iPhone killer.”

The mobile media landscape has flourished into a full-blown marketplace for advertising, rich media content, ecommerce and unparalleled utility. How can advertisers leverage new opportunities now?

In Latin America, sales of mobile phones have had a noteworthy increase in the last years.

Web visitors using a mobile device increased 34 percent year-over-year, from 42.5 million mobile Web visitors in July 2008 to 56.9 million in July 2009 according to The Nielsen Company.