A small army of robots is infiltrating the sewers in our central cities. Their mission? To deliver the blazing speed of fiber optics without digging up the streets-a slow, costly and unpopular process.

Slinking through sewers may sound like a messy proposition, but it has earned $100 million in venture capital for Silver Spring, MD-based CityNet Telecommunications-the company that hopes to use the sewer robots to wire up cities throughout the United States. "The one clear pathway that gets you down the street and into every building is the water and sewer system," says CityNet's CEO Robert Berger, a former telecommunications lawyer and current vice chairman for the Washington Suburban Sanitary Commission in Maryland.

Robots have been inspecting, cleaning and repairing sewers since the 1970s, but they didn't begin tackling telecommunication's "last mile" until the late 1980s, when Tokyo planners and robot maker Nippon Hume saw an opportunity to string bandwidth under Tokyo's narrow, congested streets.

Sewer robots have since lit up over 900 kilometers of pipes across Japan. Networking firms in Europe joined the game three years ago, but it wasn't until this winter that North American firms got started using robots built by Robotics Cabling of Berlin-which acquired and upgraded Nippon Hume's technology-as well as competing robots from Zrich-based KA-TE.