Internet telephony and chat service provider Skype, owned by eBay, today announced a potentially game-changing move, opening up to the Session Initiation Protocol (SIP) standard for its VoIP services. As evidenced by the discussion going on at Techmeme, the beta program being rolled out by the company marks a clear initiative to target enterprise customers and open up to new revenue streams. According to the Wall Steet Journal, the new beta software - uncreatively named Skype For SIP for Business users - is expected to allow employees to make domestic and international calls using regular office telephones (PBX systems) instead of using a computer and a headset for VoIP calls, which 35% of Skype's customers are already using for business purposes apparently.