Wireless billing vendor Validas analyzed the billing records of 20,000 wireless customers from January to May 2010 and discovered that Verizon Wireless customers top the charts in smartphone data usage. According to the compiled data, Verizon Wireless smartphone users consume 421MB per month, a figure that surprisingly tops iPhone users on AT&T who consume an average of 338MB of data per month. Despite the popularity of the iPhone — and its perception as a data-hungry device — Verizon Wireless also saw the largest increase in data usage per user, jumping from 48.2MB to 147.2MB per month. Verizon Wireless customers also topped AT&T amongst heavy data users with 4% of customers using 2GB or more per month as compared to 1.6% on AT&T. Not surprisingly, only 1/5th of 1% of Verizon and AT&T customers consumed more than 5GB per month, presumably due to usage caps imposed on some data plans. Wonder how those tiered data plans already in effect on AT&T (and rumored to be coming to VZW) will effect these numbers in the second half of the year?