(FORTUNE Small Business) – Eriksen Translations employs some 5,000 freelancers all over the world to translate documents in 75 languages for business clients. Eager to trim its exorbitant overseas phone bills, the Brooklyn-based company recently signed on to Skype, a peer-to-peer service that allows subscribers to speak to each other over the Internet free. (Skype makes money by charging for calls to land lines and cellphones.)

Skype was founded in 2003 by Niklas Zennstrom and Janus Friis, creators of the music file-sharing service Kazaa. Although a host of competitors are breathing down its neck, including Microsoft Messenger and the recently announced Google Talk service, Skype is currently the market leader, with 51 million users worldwide. Users simply plug a microphone into a PC, download Skype's free software, and start talking. The service helped Eriksen cut its monthly phone costs by 10% between July 2004 and July 2005, the firm says. Revenues grew by 65% over the same period. One caveat: Like most freeware providers, Skype does not guarantee the quality of its free service. --C.W.