Facebook and Google appear to be courting the graces of Skype. A source close to Facebook recently told Reuters that CEO Mark Zuckerberg is thinking about buying Skype outright, as part of a deal that could be worth $3 to $4 billion. A second source, meanwhile, claimed that both Facebook and Google are more interested in forming a joint venture with the teleconferencing company, which has yet to issue an IPO. With discussions still in a nascent stage, both suitors are playing their cards close to their chests, while Skype, rather coyly, has declined to comment on the speculation. At this point, details are still hazy and rumor-infused, though it's certainly not shocking to hear these kinds of murmurs buzzing around. Skype's been integrating Facebook more deeply into its software for a while now and has gradually branched out to Android, as well (albeit with mixed results). Both Facebook and Google would also stand to benefit from Skype's millions of users and all the targeted advertising potential they'd offer. Until we receive more substantiated reports, however, all discussions of possible unions remain restricted to the realm of conjecture.