Every day, the Fortune staff spends hours poring over tech stories, posts, and reviews from all over the Web to keep tabs on the companies that matter. We’ve assembled the weekend’s most newsworthy bits below.

• Microsoft CEO Steve Ballmer plans to sell some 75 million, or 12%, of his company shares “to gain financial diversification and to assist in tax planning.” (To date, Ballmer has sold 49 million shares, earning him $1.3 billion.) (Boy Genius Report)
• Amazon already owns Zappos and Woot. So what’s next? Diapers, apparently. Today, the company plans to announce the acquisition of Quidsi, parent company to web sites like Diapers.com and Soap.com for $540 million, or $200 million over what the company was valued at during its latest round of funding. (Fortune)
• Following in Facebook’s footsteps, Amazon is testing a “Like” button of its own, which could prove useful when site members are weighing purchases. (Times of the Internet)

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  Tesla co-founder Ian Wright raised $5 million for his Silicon Valley-based startup, Wrightspeed, which makes high performance, electric-powered sports cars. (Smart Energy News)

• Verizon is testing a $69.99 “all-you-can-eat” data/text plan and 450 minutes of voice with a select group of users. (UberGizmo)
• Dell’s Windows Phone 7-loaded Venue Pro smartphone from T-Mobile, the very same model the company gave to some 25,000 of its own employees in lieu of BlackBerry units, launches on the 8th. (Pocket Now)
• Quova, which helps online retailers, government agencies and other organizations determine where their web site visitors are located, has been snapped up by Neustar for an undisclosed amount. The company claims to power 95% of all online location searches. (Deals & More)
• Blackberry Storm 3 specs leaked, and as expected, they’re pretty standard as far as smart phones go: an 8MP camera, 8GB of storage, 3.7-inch screen and a 1GHz processor. (SlashGear)
• The top 10 Twitter trends of last week included: “U.S. Election” (understandably), “Halloween,” “Brazilian politics” due to the election of the country’s first female president, troubled pop tartlet Demi Lovato, and uh, Miss Venezuela. (What the Trend)
• RockMelt, the social media-focused web browser developed by former OpsWare employees Tim Howes and Eric Vishria, and backed by Andreesen Horowitz and VMWare CEO Diane Greene, just emerged from stealth mode. Built on top of Google’s Chrome platform, RockMelt integrates users’ social media accounts into slim left and ride side bars in the browser window. (Screengrab below.)