
There are an increasing number of Voice over IP (VoIP, also known and Internet phone) services. Most of them charge monthly fees and provide the equipment at little or no cost. Ooma takes the reverse approach, charging about $250 for the Ooma core system and providing free domestic calls (and very low cost international calls). A premier service for $19.99/month adds a second line, call screening, voicemail forwarding and other features.
Another option to consider is Skype. that provides an al a carte way to purchase features, Vonage or VoIP services provided by cable services or IPTV services such as AT&T U-verse.