Brian Gabrielson is used to the first week of January being a busy one at staffing firm Robert Half Technology in Phoenix. This year, though, demand from Arizona companies seeking high-tech employees hit with three times its usual force, leaving division director Gabrielson surprised. "We took 32 new positions just yesterday alone. That's a phenomenal number," he said. "It's been a steamroller." The market for high-tech jobs is picking up again in Arizona. Staffing firms and others in the high-tech arena say they started to notice demand rising last summer, and that it began accelerating even more in November. An...