Telefonica Launches "2 Numbers, 1 Phone" Service

Many people use multiple mobile phone numbers, often to separate work from personal calling, or to reduce long-distance charges across national borders. Most often the use of different numbers requires use of separate phones, in other cases only different subscriber information modules.

Telefonica has introduced a "Second Line" service that allows use of two discrete numbers on a single phone and using a single SIM, with services provided by fonYou, a Barcelona-based cloud telephony company.

http://ipcarrier.blogspot.com/2011/02/fonyou-mobile-cloud-telephony-for.html

The Second Line service also enables visual voicemail, a real-time call register and advanced filtering and blocking functions for incoming calls.

Telefonica chooses fonYou for cloud telephony