Last week's announcement of Google Voice was a shot across bow of the telecommunications industry. While Verizon and other carriers will experience pricing pressure on some of the add-on services that they give customers, companies that provide Internet-based voice-over-IP (VOIP) may be most threatened by Google Voice, which will let users make calls within the U.S. at no cost, and international calls at an inexpensive rate.

Take Jajah, an Internet telephone service that recently scored nearly $2.8 million in a round of funding. Jajah uses VOIP to connect landlines and mobile phones at a low cost.

Investor and entrepreneur Paul Kedrosky predicts Google will have the same impact on Internet telephony as the company has had on search engines.