XM Radio is Satellite Radio, it will work anywhere in the world! The thing is you have to pay for it on a monthly basis ($10 us dollars a month).
You don't have to put it in your car, you can just have it for a radio in your house, of course again you would have to buy the special radio that would hold it hehe.
But I love mine, they do alot of specials on the Beatles on the their 60's channel. They have over 120 channels to listen to, and all commercial free, which is why you have to pay for it