Apple Inc.’s iTunes online store was the third-largest overall music retailer in the United States, leapfrogging ahead of Amazon.com and Target Corp. in units sold, a market research firm said Friday.

ITunes had a 9.8 percent market share in the first quarter, ranking behind Wal-Mart Stores Inc.’s 15.8 percent and Best Buy Co.’s 13.8 percent, according to The NPD Group. Online retailer Amazon.com’s share was 6.7 percent, slightly ahead of Target’s 6.6 percent, NPD said.

Forget the clicker: A new technology in Japan could let you control electronic devices without lifting a finger simply by reading brain activity.

The “brain-machine interface” developed by Hitachi Inc. analyzes slight changes in the brain’s blood flow and translates brain motion into electric signals.

A cap connects by optical fibers to a mapping device, which links, in turn, to a toy train set via a control computer and motor during one recent demonstration at Hitachi’s Advanced Research Laboratory in Hatoyama, just outside Tokyo.

“Take a deep breath and relax,” said Kei Utsugi, a researcher, while demonstrating the device on Wednesday.

At his prompting, a reporter did simple calculations in her head, and the train sprang forward — apparently indicating activity in the brain’s frontal cortex, which handles problem solving.

Activating that region of the brain — by doing sums or singing a song — is what makes the train run, according to Utsugi. When one stops the calculations, the train stops, too.

Underlying Hitachi’s brain-machine interface is a technology called optical topography, which sends a small amount of infrared light through the brain’s surface to map out changes in blood flow.

Although brain-machine interface technology has traditionally focused on medical uses, makers like Hitachi and Japanese automaker Honda Motor Co. have been racing to refine the technology for commercial application.

Hitachi’s scientists are set to develop a brain TV remote controller letting users turn a TV on and off or switch channels by only thinking.

Creative has announced a new version of its feature-free Zen Stone music player– the Zen Stone Plus. The MP3 player has a 2GB flash memory and will have a small circular blue display. This contrasts with the Stone, launched last month, which had no screen, aping Apple’s tiny iPod Shuffle player.

The Zen Stone Plus has a built-in FM radio, clock and stopwatch as well as a microphone, meaning the player will be able to double as a voice recorder.

Songs can be dragged and dropped on to the Stone Plus, with no special software required. If it works the same way as the Stone, a reboot will be required the first time you hook up the player to your PC, after which you will be able to plug it in via a USB port and copy tracks straight to it.

The 2GB Stone Plus boasts twice the capacity of the Stone– at the lowest sampling rate of 64K, it will be able to accommodate as many as 1,000 songs. In practice, most tracks are ripped from CD or downloaded from an online store at higher bitrates than this, so storing 500 to 700 songs on the Stone Plus may be a more realistic figure.

IBM has released to the public a beta version of DB2 Viper 2, the newest incarnation of its data server.

Less than a year after releasing Viper, IBM is promising Viper 2 will expand on its predecessor by simplifying the development and administration of XML in DB2 with features such as a built-in SQL function that allows users to transform XML documents using an XML style sheet.

Other enhancements include better integration of workload management functionality into the database engine and automated backup maintenance.

“The enhanced security and workload management features of Viper 2 will extend the technological lead that DB2 has on the competition,” said Bernie Spang, IBM’s director of data servers.

A Microsoft security executive released data Thursday showing that, six months after shipping Windows Vista, his company has left more publicly disclosed Vista bugs unpatched than it did with Windows XP.

In total, Microsoft has patched 12 out of 27 disclosed Vista vulnerabilities in the six months after it first shipped last November. During XP’s first six months, Microsoft’s security team patched 36 out of 39 known bugs.

The data was published by Jeff Jones, a Microsoft security strategy director, who said that overall, Vista was doing better than XP. “Windows Vista continues to show a trend of fewer total and fewer high-severity vulnerabilities at the six month mark compared to its predecessor product, Windows XP,” he wrote.

Jones didn’t address the larger number of unpatched vulnerabilities, but he did note most of the unpatched Vista bugs were not critical. Microsoft had left only one high-severity Vista vulnerability unpatched during the period. At the end of XP’s first six months, there were two high-severity bugs that were unpatched.

The Defense Department took as many as 1,500 computers off line because of a cyber attack, Pentagon officials said Thursday.

Few details were released about the attack, which happened Wednesday, but Defense Secretary Robert Gates said the computer systems would be working again soon.

Gates said the Pentagon sees hundreds of attacks a day, and this one had no adverse impact on department operations. Employees whose computers were affected could still use their handheld BlackBerries.

During a press briefing Gates said: “We obviously have redundant systems in place. … There will be some administrative disruptions and personal inconveniences.”

He said the Pentagon shut the computers down when a penetration of the system was detected, and the cause is still being investigated.