As Verizon Wireless took orders from its customers for Apple’s iPhone 4, rival AT&T — until now, the exclusive iPhone carrier in the U.S. — this week enlisted a new soldier in Google’s Android army.

Demonstrating a shift in allegiance from Apple to Android, AT&T described the Motorola Atrix 4G as “the world’s most powerful smartphone” and listed numerous high-end features. To get the most out of the Atrix 4G* (*4G speeds available in limited areas, according to an AT&T news release), Android fans will need monthly voice, data and tethering plans — and accessories priced for early adopters.

Pre-orders begin Feb. 13. The Atrix 4G itself — which runs the Android 2.2 operating system — will be available by March 6 at a cost of 9.99* (*for customers who commit to a new two-year contract).

Among those high-end features are tethering* (*but that will require a Motorola Laptop Dock). The Atrix packaged with the dock costs 9.99* (*with a two-year data and tethering contract — and as part of the deal, AT&T says it will send you a 0 Visa gift-card rebate). Separately, the dock costs 9.99.

The Atrix also can connect to high-definition big-screen TVs and displays* (*with a 9.99 HD Multimedia Dock, which comes with a Bluetooth keyboard, mouse and remote control). The Atrix will even work as a remote for AT&T’s U-Verse TV service — or owners can watch programming with the preinstalled AT&T

U-Verse Live app* (*with service for .99 a month).

Spammy search results? Mountain View Internet juggernaut Google promised last month that its engineers are working on ridding spammy junk content from their results.

Redwood City online search upstart Blekko this week went a step further, banning from its results 20 sites identified most often as “spam” by its users. The sites “are literally responsible for millions of pages on the Web that our users say are just not helpful and they’d prefer they were banned permanently,” Blekko CEO Rich Skrenta charged in a news release. “So we’re going to do that for them.”

At the top of the list was eHow, a collection of inexpensively produced how-to articles from Demand Media, a Santa Monica company that sold its stock in an initial public offering last month.

Blekko has raised million from U.S. Venture Partners, CMEA Capital and such angel investors as Ron Conway, Mike Maples, Jeff Clavier and Marc Andreessen.

Online real estate: Tech Notebook used to be devoted to Zillow and its home-value “Zestimates,” but we’ve tried to avoid the Seattle online upstart’s site in recent years because it only reminds us how much our mortgage is underwater. Now it looks like we’ll have to try to stay away from the Yahoo Real Estate site, too.