Grammy award winning (and again recently nominated) Spanish Harlem Orchestra is basically a group of All-Star latin Jazz and Salsa musicians, led by accomplished pianist Oscar Hernandez. I had an opportunity to meet many of the band members, and yes we talked about how it is they communicate with their relatives world wide. Most are using mobile phones with calling cards it seems. I told them about Jajah and Maxroam as options, which I think they appreciated.
If you're in the Bay Area... Get tickets to see these guys while you still can.