Let's think about this for a second. According to a deep look at the latest census statistics (I just googled it) the United States has a population of 307,006,550 as of July 2009. According to the latest sales figures provided by Nintendo, the DS, the company's dual-screened handheld in four different models, has sold over 50,000,000 units in the United States.
With seven years since launch, the Nintendo DS has sold a F***TON of units. That means it's possible roughly 1 in every six people in the United States have owned a Nintendo DS at some time.
I'd rather not think about the worldwide totals at the moment. I think I need to lie down. Do you have 50 Million of anything? Let us know in the comments.