His preeminence, oh lordship, oh liege, (uh hem) Walt Mossberg, just returned from a US test flight on a small business jet equipped with Aircell's new Gogo WiFi service. He tested multiple devices including Dell and Apple laptops, a Blackberry, iPhone, and WinMo-based cell and found them to all perform flawlessly, albeit, at speeds ranging from 266Kbps to about 1.4Mbps. Typical speeds clocked in at 500Kbps to 600Kbps -- upload speeds were a more modest 250Kbps to 300Kbps. Aircell promises a similar experience on large commercial planes with multiple connected devices. These speeds were good enough for Walt to surf the Web and check email (both prioritized on Gogo's network) as he would in the office but not quite fast enough to deliver smooth video streaming. Fortunately, (or unfortunately depending upon your opinion) the service blocks all VoIP services like Skype. Gogo WiFi will cost $12.95 for flights of three hours or longer, and $9.95 for shorter trips -- free for limited access to AA's website, Frommer's online travel guides, and select articles from The Wall Street Journal. It's scheduled to launch next month on American Airline flights between New York and LA, San Francisco, and Miami -- it will then head to Virgin America and other airlines if things go well. See Walt's head talk from the bowels of embedded video after the break.