TECHNOLOGY TO KEEP IN TOUCH Contractors are finding that cellular phones and other high-tech communication tools can save footsteps, time, and money by David Dobbs Cellular Phones Until recently, cellular phones (also called mobile phones) have been too expensive for most small builders. But improving technology and a larger customer base have brought cellular phone prices within reason. The units themselves now sell for as little as $200, and monthly service and per-minute air-time charges are also dropping. As cellular gets more affordable, more builders are finding that when your dashboard is your desk, it pays to have a phone on it. Cellular phones work by sending radio signals to a relay tower, which in turn either broadcasts the signal through the air or through