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 day’s most newsworthy bits below.

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  Dozens of online stores — including Toys ‘R’ Us, Barnes & Noble (BKS), and Radio Shack (RSH) — have teamed up to launch a counter-offensive to Yahoo’s Amazon Prime service, offering a cooperative loyalty program called ShopRunner. The service offers free 2-day shipping and free returns. (The Wall Street Journal)
• According to StatCounter, Internet Explorer, still the world’s most widely used web browser, dropped below a 50% share of the market, down from nearly 60% a year ago. (Google 24/7)
• GigaOm has a nice roundup of startup post-mortems, including comments from Wesabe co-founder Marc Hedlund, whose personal savings site folded thanks to Mint.com’s success, and Standout Jobs co-founder Ben Yoskovitz, who sold the startup back in May and has moved on to a seed fun/incubator called Year One Labs. (GigaOm)
• Foursquare attributes its recent 11-hour crash, the longest downtime in the social network’s history, to an overload of what they call “shards,” packets of their database where they store check-ins. (Mashable)
• As part of its top-secret event tomorrow, Facebook may unveil a redesign. (TechCrunch)
• AppNexus, a New York City-based startup and ad platform, announced it raised $50 million in funding. Investors now include Microsoft (MSFT), Venrock, Kodiak Venture Partners and First Round Capital. (MediaBeat)
• Oracle (ORCL) plans to buy enterprise single sign-on technology vendor Passlogix, which should go a ways to boosting the company’s security offerings. (The New York Times/IDG)
• Electronic Arts (ERTS) says that the latest installment of its soccer game franchise, FIFA 11, sold 2.6 million copies in North America and Europe since last week’s launch, making it the “fastest-selling sports game ever.” (Joystiq)
• Motorola (MOT) co-CEO Sanjay Jha says he’s open to the idea of the company developing phones for Microsoft’s Windows Phone 7 OS despite the patent-infringement suit Microsoft filed against them. (The Wall Street Journal)
• Samsung’s impending tablet, the Galaxy Tab, will be the latest mobile device to benefit by employing that now-famously tough and er, pseudo scratch-resistent “Gorilla Glass.” (Slash Phone)
• According to its CEO, Blippy users are sharing $500,000 in purchases each day. The controversial service, which has raised $13 million in funding and is valued at $50 million, lets its users share purchases and prices with friends. (Trailer below.) (TechCrunch)

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