Want to make a long distance call on the cheap? You've got plenty of options, including the likes of Google Voice, Skype, and numerous other VoIP providers. But things can get a little tricky if you don't know someone's phone number, or they don't already have Skype installed. Today VoIP service provider Jajah, which was acquired by Telefónica in 2009, has a solution that will appeal to Facebook users: a new feature for its Android application (iPhone's coming soon) that lets you call your Facebook contacts. That sounds a bit confusing, but the feature is straightforward in practice.