The U.S. Geological Survey (usgs.gov) has a feed for earthquakes occurring throughout the world in the past week. This data contains latitudes and longitudes.
This example uses two Location Builder modules to define two towns in Alaska: one in the northwest and the other in the southeast. Our earthquake feed is piped into a Filter module, and four rules are added to allow only items where the latitude and longitude fall within a geographic area.
That area is defined by a rectangle whose upper-left and lower-right corners are the two towns defined by Location Builder. We wire them into the value field of each Filter rule.
This example also shows that it's possible to wire some modules into more than one end-point. Here each Location Builder module has two output wires, each connecting to a separate filter rule.
Pipe Web Address: http://pipes.yahoo.com/pipes_team/WqQBeONS3BGmcqMz8jxBKg