Hi
I read final report on the failed "Broadband through Electric Wire" trial project in UK from NORTEL.
The street lamp etc will turn into transmitter and the ISP cann't maintain privacy for the customer.
However in German and Austria, PLC projects are succesful with more than 10 million subscriber. Another failed broadband is Horizontal Blanking from Metabox (creator of AmiJoe).
The new Proxim Wi-Fi wireless device can reach up to 10 Miles at speed of 10 Mbps. NYC Wireless (NY, USA) plan to use this device. Perhaps there will be similar effort in London / other cities in UK.
Unfortunately the ISP / backbone companies are against Free Wi-Fi wireless internet access, because the public can use their bandwidth illegally.