Sprint Nextel on Wednesday unveiled a new laptop modem that will allow users to switch between the company’s normal cellular network and the new high-speed WiMax network. The Overland Park, Kan.-based wireless carrier said the USB Modem U300 will go on sale Sunday in Baltimore, the only market where Sprint is currently offering the so-called fourth-generation wireless service under the Xohm brand. WiMax, similar to the WiFi broadband services found in airports and coffee shops, can cover an entire city.
