This is a tip that I learned last year during the hurricanes (Katrina and Rita). In most cases this was the only way to contact family members in Louisiana. I think with hurricane season in full force (no pun intended) this is a good thing to know. When a land line is unavailable and all you have is a cell phone even that is useless sometimes. During storms (or in "dead zones" while traveling) when you don't have a signal and a call won't go through, try a text message.