Google is disappointed with the lack of breakthrough investment ideas in the green technology sector but the company is working to develop its own new mirror technology that could reduce the cost of building solar thermal plants by a quarter or more.

“We’ve been looking at very unusual materials for the mirrors both for the reflective surface as well as the substrate that the mirror is mounted on,” the company’s green energy czar Bill Weihl told Reuters Global Climate and Alternative Energy Summit in San Francisco on Wednesday.

Google, known for its Internet search engine, in late 2007 said it would invest in companies and do research of its own to produce affordable renewable energy within a few years.

The company’s engineers have been focused on solar thermal technology, in which the sun’s energy is used to heat up a substance that produces steam to turn a turbine. Mirrors focus the sun’s rays on the heated substance.

Weihl said Google is looking to cut the cost of making heliostats, the fields of mirrors that have to track the sun, by at least a factor of two, “ideally a factor of three or four.”

“Typically what we’re seeing is $2.50 to $4 a watt (for) capital cost,” Weihl said. “So a 250 megawatt installation would be $600 million to a $1 billion. It’s a lot of money.”

A new security vulnerability involving the Server Message Block protocol, used for Windows file-sharing, can allow a remote attacker to take control of a vulnerable Vista, Server 2008 or Windows 7 RC computer, in addition to causing it to crash as previously reported.

Security researchers found that the bug could be hit to cause the venerable Blue Screen of Death computer crash if a PC has file sharing enabled. But in Security Advisory 975497, released yesterday, Microsoft wrote that “an attacker who successfully exploited this vulnerability could take complete control of an affected system. Most attempts to exploit this vulnerability will cause an affected system to stop responding and restart.”

A hole that allows for assuming control of a computer from across a network is about as bad as it gets, and I’ve asked for confirmation from Microsoft that this is in fact possible with this SMB flaw. Windows XP, 2000 and Server 2008 R2 are not at risk, nor is Windows 7 RTM.

Apple rolled out the world’s smallest music player — and the first music player to talk to you — the new iPod shuffle, priced at $59 with 2GB of storage. Consumers can also opt for a 4GB shuffle for $79.

At the other end of the spectrum, Apple launched the new iPod nano, complete with a video camera, microphone and speaker. That means music fans can shoot video, view it on their nano, and upload it to YouTube.

Taking a page from the Microsoft Zune playbook, the new nano also features a built-in FM radio with live pause and iTunes tagging, as well as a built-in pedometer. Live pause lets iPod nano users pause and resume playing FM radio shows. iTunes Tagging lets users tag, preview and purchase songs they like when they sync with iTunes. An 8GB nano sells for $149 and a 16GB model for $179.

Apple also rolled out a new iPod touch lineup with a starting price of $199. The iPod touch is similar to an iPhone without the calling capabilities. It offers a multi-touch user interface, a 3.5-inch widescreen glass display, Wi-Fi, Bluetooth and a built-in accelerometer and speaker.

Mozilla is pushing out a new release of its flagship Firefox browser that fixes critical security vulnerabilities in the software and, for the first time, checks to see if the browser’s Flash Player is up-to-date.

The Firefox 3.5.3 and 3.0.14 updates were released Wednesday, a day after Microsoft pushed out its monthly set of security patches.

By actively checking for up-to-date Flash software, Mozilla hopes to give users a smoother, and more secure, Web browsing experience. Mozilla decided to focus on the Flash Player “both because of its popularity and because some studies have shown that as many as 80% of users currently have an out of date version,” said Mozilla spokesman Johnathan Nightingale in a recent blog post on the issue. “Mozilla will work with other plugin vendors to provide similar checks for their products in the future,” he added.

Computer criminals have increasingly turned to bugs in add-on software such as Flash and QuickTime as they look for new ways to hack into PCs.