Quick quiz: Who are the three largest Internet companies in the world by market capitalization? If you guessed Google and Amazon you got two right, but I’m betting few of our American readers guessed the third

Professional social network LinkedIn now has 70 million members, according to the company’s home page. The company hit 60 million users in February, and has been growing fast, especially in international markets.

Editor’s note : Guest author Steve Cheney is an entrepreneur and formerly an engineer & programmer specializing in web and mobile technologies.

We haven’t posted anything about online music and video streaming service Muziic so far, although I’ve been aware of its existence for a while (it has bagged a lot of media coverage since its debut in March 2009 and with the release of the fun Muziic DJ tool). The small, self-funded, father-son start up based in a small Iowa town offers its streaming service on a wide variety of platforms, including a Web player, desktop software client, Facebook , iPhone and iPad apps and more. Questions about its legality abound , but it sure has been successful in finding an audience: the company recently added a counter to its main website showing the number of streams to date

This ia a guest post by Justin Davies , founder of NinetyTen , a UK-based consultancy providing mobile community and location aware solutions to companies. Davies also founded the now defunct BuddyPing , an early mobile social networking community based on the realtime location of users, and thus has few opinions about the rise of Foursquare and others…

There was a time when Facebook was at the forefront of mobile app development. Before there was even an App Store, the web app Facebook put out that was optimized for the iPhone was brilliant . Then the App Store came and with it was a great Facebook native app.