Priciest mobile Internet in the world: US

Japan is the cheapest place to have a smartphone with a data plan, while the U.S. ranks highest in mobile Internet costs per month.

U.S. users pay more than $40 a month for 2GB of data (the going threshold for new capped data plans). On the other end of the scale, Japanese mobile phone callers pay just a touch over $10 a month for the same plan. Both were priced at 4G LTE speeds. Verizon's rates spiked the U.S. to the most expensive, but the current plans on its website show a price of $30 for 2GB, on both smartphones and mobile broadband devices like tablets. At $30, the U.S. would be more in line with the middle of the pack, with China -- if Verizon was its only carrier. But others can be interpreted as being over the $40 marker, such as T-Mobile's Unlimited Plus Value Plan for families, with an entry point of $39.99 per line for two lines of 1,000 minutes, unlimited text and data (2GB of high-speed, then throttled down over that).