The AT&T $10/Day International Plan is great, but can lull us into a false sense of security. I went ashore at Punta Arenas in December, and used the wireless service for data etc., then forgot to switch it back off when we boarded (it's still OK in port, picking up the signal from a tower on land). Next morning, at sea, I woke up to a string of text messages from AT&T telling me I had run up large overage charges. This despite having use of the ship's wi-fi for the duration of the cruise. Pays to be aware and cautious when traveling abroad....