Anybody who's spent an afternoon walking around Upper Street, iBook in hand, trying to log on to Islington council's "Technology Mile" service may smirk, but a new report says Londoners are the most wifi-happy people on the planet. According to the Wi-Fi Hotspot Index, networks set up by the likes of BT and The Cloud in London account for one tenth of the UK's wireless usage, and just over 1% of the worldwide total......