Sonnet Technologies announced its 1.2GHz processor upgrade program for 550MHz and 667MHz G4 PowerBooks on Tuesday. After placing an order, PowerBook owners ship their Mac in a Sonnet-supplied box. The company replaces the PowerBook processor with a 1.2GHz Freescale 7457 G4 chip with 512K L2 cache, tests the system, and ships it back. The service is priced at US$499.95. More information is available at the Sonnet Web site.