Paper currencies have been around since the 10th century, and today thousands of banknotes are in circulation around the world. Some are colorful, some are tiny, and some are downright bizarre. Check out the video for a quick tour of some of the most interesting bills out there.
Images via Banknote World
Routers on 600 buses and taxis allow free Internet access and collect data for city planners.
A massive mobile Wi-Fi network that could be a model for many cities was launched in the city of Porto, Portugal, this fall. Buses and taxis are equipped with routers that serve as mobile Wi-Fi hot spots for tens of thousands of riders. The routers also collect data from the vehicles—and from sensors on trash bins around the city—and relay it back to city offices to help with civic planning.