Opera now has more than 20 million users surfing the Web with its Opera Mini browser, and it has seen an 18% growth in data transfer, according to the company's latest State of the Mobile Web report.

Opera Mini is a lightweight, Java-based browser that can work on low-end handsets and smartphones like the BlackBerry or ones powered by Microsoft's Windows Mobile. It eases the hardware and connectivity needs of the handset by rendering Web pages on an Opera server and then sending it to the device. For January, the company said its mobile users viewed more than 1 PB of data.

Russia, Indonesia, Ukraine, China, and India were the top five users of Opera Mini, but the company also saw solid growth rates from established markets. Opera named Facebook as a destination that was in most-visited list in multiple regions, particularly the Middle East.

"Looking back on a full year of mobile Web growth, it is easy to see why mobile devices will become the primary device for Web usage in most of the world," said Jon von Tetzchner, Opera's CEO, in a statement. "Developing countries may lead the way due to the sheer prevalence of mobile devices versus PCs, but the solid growth rates in developed countries such as the United States, the United Kingdom and Germany, show the entire world is moving in this direction."

Opera continues to carve out market share in the mobile space with its Mini and Opera Mobile browsers, but the field is expected to grow increasingly crowded as more consumers surf the Web from a mobile phone. In addition to on-deck browsers like Apple's mobile Safari, companies like Mozilla and Skyfire are trying to become the main browser for cell phone users.

Smartphones can lead to productivity boosts in a workforce, but they can also lead to questions about policies and mobile security. InformationWeek evaluated the best smartphone practices for businesses, and the report can be found here (registration required).