Yahoo Messenger on the line

Now we know why Yahoo dubbed version 7 of its popular IM tool Yahoo Messenger with Voice. Today the company revealed that Yahoo Messenger will offer Net phone plans at half the price of Skype's per-minute domestic fees. For a penny a minute, Yahoo's free IM client will let you call any U.S. landline or cell phone; international calls will cost 2 cents per minute. Skype, also a free download, charges 2 cents per minute for calls stateside and to Canada, Europe, Australia, New Zealand, and Chile. Skype (now owned by eBay) just added video calling, which Yahoo Messenger already offers.

A bundle of companies are racing to corner the market on communications services in a "Voice 2.0" world that merges telecom and Net tools. Fellow CNET editor Felisa Yang picks these five VoIP plans, which stand out from the crowd. Many IM tools offer voice calling--but most let you ring only fellow buddies on the same IM client, not via telephone.