Israel Aerospace Industries unveiled plans for TaxiBot at the Farnborough Air Show. The semi-robotic vehicle, controlled by a plane’s pilot, tows the plane from the terminal gate to the takeoff point without the need to operate the plane’s engines. It can save 1000 litres of fuel for a Boeing 747.
http://www.globes.co.il/serveen/globes/docview.asp?did=1000763363&fid=1725