Every day, millions of people check in on Foursquare. We took a year's worth of check-ins in New York City and Tokyo and plotted them on a map. Each dot represents a single check-in, while the straight lines link sequential check-ins. What you can see here represents the power of check-in data -- on Foursquare, every city around the world pulses with activity around places every hour of every day. Related: Also see our data visualization of four days worth of Foursquare check-ins in New York CIty during Hurricane Sandy (and the subsequent power outage) during October 2012: http://vimeo.com/52883962.

Each dot represents a check-in during this 96 hour period. Super fascinating to see the different types of check-ins ripple across the city as time of day effects the rhythm of all of these individuals in a fairly regular pattern.