Earlier this week, Sony's Consumer Electronics Show site slipped news that Skype VoIP functionality for the PlayStation Portable (PSP) will soon be added. Japan's Nikkei Net news service is reporting today that Skype functionality will be added to the PSP as early as this month. Skype's Internet phone technology will be limited to owners of the PSP Slim only. Those who own the redesigned handheld will be able to download Skype software directly onto their PSPs and then use a specially designed microphone to communicate. The Skype service will be free for PSP-to-PSP and PSP-to-PC calls. PSP Slim owners will also be able to sign up for a dedicated phone number, which Nikkei is reporting will run for 2,250 yen (about $20.70) for three months of usage. Expect more information on the service next week during the 2008 Consumer Electronics Show in Las Vegas.