Newbie's guide to VoIP

For the uniniated to the Voice over Internet Protocol
(VoIP) scene, Tom's has a general guide to the Internet telephony world, with information on the major providers such as Vonage and BroadVoice, how well 911 works in a power outage, reliability, and voice quality. They also uncover a dirty little secret of the VoIP provider world, which is that you may not necessarily be able to switch providers using the same hardware because the Analog Telephone Adapters (ATA) may be locked for one provider only (much like SIM-locked cellphones). And don't forget that the FCC requires that VoIP
always be tappable by the feds, and that the NY Times considers
VoIP insecure, for what it's worth (which is not too much in our book).