According to new research performed for Consumer Reports by bill analysis company Validas, iPhone users account for nearly twice as much data usage as the average non-iPhone smartphone user. The study found that iPhone users consume 273 MB of data per month on average, compared to just 54 MB for BlackBerry users and 150 MB for users of other smartphone platforms. Additionally, 12 percent of iPhone users consume at least 500 MB of data per month, and…