Devices like the iPhone and iPod touch may have sparked a collapse in handheld game system sales in April, new NPD data found. The overall US console market's revenue dropped 27 percent last month, but the Nintendo DS and Sony PSP accounted for 61 percent of the overall drop even though they represented just a quarter of all revenue. Nintendo was especially hard-hit as DS sales were cut by more than half versus a year ago to just 440,800.
