$3000 Voicemail Bill! Watch out if you are roaming

I just saw this on Jo-itos site and my jaw dropped because I am always roaming (well most of the time!). But I am on a different network.
The story is of a traveler from Europe who happened to travel by ship and made a call from LA. All his voicemail was counted as roaming and ended up with a bill for $3000. So if you are roaming and on T-Mobile watch out. Read more at Jo's site.