International mobile calling solutions provider Rebtel has just launched a SkypeMe-like functionality for Facebook.
Go here, complee the necessary data, and you'll have a RebMe next to your Facebook name. If one of your Facebook friends has Reb Me, you'll be able to start a Rebtel call directly from your Facebook page.
Once again, here's how Rebtel works:
You give Rebtel the phone number of a friend in another country, and they give you a local number for them.
Save this number on your mobile so you can call your friend whenever you want, for a fraction of your normal international rate.