Someone has the right idea in Italy with their prepaid data prices. Wireless Moves reports that for as little as nine Euros you can find data access on the go with mobile network operator, WIND. For 20 Euros you can get 10 GB of data in a month. When you do the conversions that roughly $25 dollars for more than twice the data as say, Verizon Wireless or AT&T here in the USA.
To find out what's available where, the site referenced in the post, the PrePaid Wireless Data Wiki is a great starting point.