Clearwire raised $600 million last week in an initial public stock offering. Now would it get on with changing Internet access as we know it?

McCaw's betting on WiMax Photo by Neal Hamberg/Bloomberg News/Landov

Clearwire, along with Sprint Nextel, will show whether mobile WiMax is commercially viable for the U.S. Internet access market. As of November, the company had 188,000 subscribers--about a 2% share--of 34 U.S. markets where it offers "pre-WiMax" technology, which provides broadband connections wirelessly to toaster-sized receivers in people's homes. But its big bet is mobile WiMax, which promises faster connections than cellular for PCs, phones, and other devices on the go. Sprint Nextel has committed $3 billion to implement mobile WiMax.

Clearwire--whose founder, Craig McCaw, still owns 49% of voting stock--raised $900 million from Intel and Motorola last summer, has borrowed $755 million since August 2005 and run up a $458 million cumulative loss. Last week, its shares were trading about 10% below the offering price. Tech-driven revolutions aren't getting any cheaper or easier.