Was reasding this section last night having lurked on Styleforum for a good while now. Came across this post and reckoned I'd do the right thing and respond! Hope it's not too late.
Anyhow, the device you are looking for is called a BGAN (Broadband Global Area Network). The Thurya mentioned above is one.
You can read all about them here....http://en.wikipedia.org/wiki/Broadba...d_availability
Now, I haved a BGAN - it's from a company called Thrane & Thrane. They are ferociously expensive to maintain as highlighted above. Maximum bandwidth - half a meg is charged at $20 per minute, but you can pear back the service in various ways to save money. Principal is just like a phone. Buy a sim card on contract and insert. Depending on the contract, some vendors will 'subsidise' your device, again just like a phone contract - you might get one free, but that will be on a contract worth $30k for the year.http://www.thrane.com/Land%20Mobile/...RER%20700.aspx
These devices are only really relevant in locations where little or no infrastructure exists. Pretty much all main centres of population - even in the least developed part of the world - has reasonable access to the internet. Asia and parts of Latin America is well served by 3G now so a MiFi will work well there. Africa not so. 3G is limited but 2G is almost everywhere. I use my BGAN mostly in Africa as I tend to travel to some very, very remote places.
However, some countries will not take kindly to bringing these into their country. Be informed.