I use the Iridium 9505A. I love the thing. It come in handy when cell coverage is not an option. I buy the pre-paid cards of 500 minutes and the time will last for a year. It works out to be about $1.30 a minute. Anywhere in the world. That's cheaper than a cell phone in some regions. It's cheap insurance. When the time is right I would love to get my hands on the new 9555.
Check this site out they seem to have some of the best pricing that I can find.
Satellite Phones, International Cell Phones, International SIM Cards and International BlackBerry® Smartphones