Welcome back to Baby Breakerdom! This time, our ongoing quest to uncover budding Rule Breakers finds us taking a hot shower, and wondering whether free calls are worth the price.

Come on in, the water's boiling
First up this week is Ausra, which aims to build the nation's largest solar thermal plant.

Confused? That's understandable. Solar thermal is the process of extracting electricity from the sun's heat. Most other solar firms, including Evergreen Solar (NASDAQ:ESLR), First Solar (NASDAQ:FSLR), SunPower (NASDAQ:SPWR), and Suntech Power (NYSE:STP), use sophisticated photovoltaic cells -- otherwise known as "solar panels" -- to convert sunlight directly into usable power.

Ausra's mechanism seems so 19th century by contrast, as if plucked from the brain of Artemus Gordon. Everything runs on ... water.

Or, more precisely, steam. Called a Compact Linear Fresnel Reflector, Ausra's plant uses mirrors that follow the path of the sun and reflect tightly focused beams of sunlight onto pipes above, boiling the water within. The resulting steam cranks a turbine, creating power. Think of it as a 19th century mill built with 21st century technology.

Cheap power 24/7
I'm fascinated with this process for several reasons. First, because it continually recycles water, it's as environmentally friendly as any solar alternative.

Second, because the mechanism's main by-product, heat, can be stored cheaply, it can be unleashed day or night to produce new steam, and thereby, new electricity. (Solar panels, by contrast, are hobbled during the evening hours.)

And third, because it uses commodity components -- mirrors, water, pipes, etc. -- Ausra's mechanism is cheap, capable of producing electricity for $0.10 per kilowatt-hour right now. Over time, Ausra says its plants will be cost-competitive with coal-fired electricity, which tends toward $0.06 per kilowatt-hour. Talk about Rule Breaking.

Don't wait in line
If there's a problem here, it's with the business model. Ausra won't sell to you or me. Not directly, at least. Ausra hopes to build for utilities. That means they'll be subject to Federal and state scrutiny as they suffer at the hands of Homer Simpson wannabes. (D'oh!)

Yet top-tier venture investors remain optimistic. Legendary venture capitalist Vinod Khosla teamed with his former firm, Kleiner Perkins Caulfield & Byers, to provide Ausra with more than $40 million in financing earlier this week.

Good move. Even if today's electric utilities are the stuff of a Dilbert cartoon, regulators are pushing for change nationwide. Here in Colorado, for example, the state requires that no less than 20% of our power come from renewable sources by 2020. And California, which is expected to play host to Ausra's first plant, is spending $3 billion on solar incentives. Ausra's not likely to pass up such incentives. Add this one to your IPO watch list, Fool.

Time for this merry-go-round to end
Can we all stop playing follow-the-Google? It's getting tough to watch. Consider the latest entrant in this me-too pageant: VoodooVox, which promises free calls to those who agree to listen to ads.

Here's how CEO J. Scott Hamilton put it, announcing $8.1 million in a series D round of financing from venture backers earlier this week:

Phone calls are the new page views, and VoodooVox's In-Call Network is the next breakthrough advertising channel. We strongly believe that most telephony services that consumers currently pay for can be delivered profitably and for less with advertising support.

The press release goes on to report that Microsoft, Nokia (NYSE:NOK), Showtime, and Virgin Mobile are among those using VoodooVox to sponsor calls. All told, VoodooVox says 300 million calls a month ring through its network.

No doubt, that's impressive. But am I the only one who thinks the bar for phone ads is higher than the bar for Web ads? I use the phone exactly because I don't want to bother with the interruptions that the Web creates. Now VoodooVox wants to stiff-arm me? Color me unenthused.

Know of a Baby Breaker we Fools should be following? Tell me. And see you back here next time when we continue our quest to find the greatest growth.

For more Rule Breaking Foolishness:

How great is growth? More than 10 stocks in the market-beating Rule Breakers portfolio, which includes Suntech Power, have at least doubled. Discover their identities with a 30-day free pass to the service. There's no obligation to subscribe.

Microsoft is an Inside Value pick.

Tim Beyers is a regular contributor to Fool.com and the Rule Breakers team. He owned shares of Nokia at the time of publication. Find Tim's portfolio here and his latest blog commentary here. The Motley Fool's disclosure policy is a rebel on Wall Street.