Opera Software on Tuesday launched in beta an upgrade of its Opera Mini mobile browser, which has been enhanced with better support for YouTube video.

Along with the preview release of Opera Mini 4.2, the Norwegian company said more than 20 million people were using the mobile browser worldwide. Opera said the increased traffic has led it to open an Opera Mini server park in the United States to boost browsing speeds in the U.S. and the Asia-Pacific region.

The beta version of the browser includes a colorful selection of new skins, better support for YouTube and other online video services on a wider selection of mobile phones, including new Sony Ericsson or Nokia phones. Improvements in the browser's Opera Link feature allow users to share notes between their phones and PCs, in addition to their bookmarks and recently visited URLs.

In the statement announcing the beta release, analyst firm IDC said it has seen a 10% average growth in the number of Opera Mini users worldwide each month.

Opera Software, which also makes a full desktop browser for Microsoft Windows and Apple machines, has created a version of the Opera Mini for the iPhone. Apple, however, refuses to offer the browser through its App Store.

Apple put the kibosh to Opera Mini because it would compete with the company's Safari browser, which ships with the iPhone, Opera chief executive Jon Stephenson von Tetzchner told The New York Times.

Opera browsers are available at no charge.