ThingSpeak is a cloud based internet of things service that allows you to send HTTP requests to interface to a channel of data. You can send data, retrieve data, and even perform actions based on data values. You can configure an Arduino to send data readings to ThingSpeak using HTTP requests.

This video shows the basics of ThingSpeak

This video shows how to obtain data from ThingSpeak

This video is a demo of the ThingSpeak<->Arduino project

Arduino-ThingSpeak project sketch:  elen215_thingspeakandwebserver