On a recent business trip to Hong Kong, Raju Gulabani didn’t pay a dime for his international phone calls. Connected to a Wi-Fi network in his hotel and using an iPaq personal digital assistant, the 45-year-old former Microsoft manager routinely dialed his family and business associates in the Seattle area. Gulabani, the founder and chief executive of TeleSym, was not part of some international phone calling scam. He was simply using his company’s new software, which allows users of laptops, PDAs and other devices to bypass the traditional phone network and make calls over wireless Internet networks. With a high-quality sound and a cheap price, Gulabani thinks the SymPhone software will transform the way phone calls are made. Some big name investors tend to agree.