Remember when Nintendo announced that the 3DS' StreetPass function would be improved so that you would get tagged whenever you passed through a Nintendo Zone location? The way the system works, two 3DS owners don't have to be present at the same time. Instead, you'll be able to tag the last person who had been hanging out in that spot.
That's all well and good in the sparse areas of the US, but it still isn't good enough if it's limited to just one tag. But later this month, Nintendo will bump that number up so that you'll receive data from the last six people. That's much, much better and should have been such from the beginning.
You still need to be present at the Nintendo Zone location (Best Buy, Starbucks, etc.) for a minute or so to get the data. It's not like you can just drive by in your car and get tagged.