This is an easy solution to get a quality internet connection when in London and the United Kingdom while still avoiding sky-high roaming costs. You simply rent the tiny pocket Wi-fi device Travelers Wifi and you'll have an unlimited data connection and 2GB per day in full high speed 4G data in all of the United Kingdom, for up to 5 devices. And it's simple to get. Book it in advance on its website and then simply pick it up upon arrival in London at the terminal s 2, 3, 4 and 5 at Heathrow Airport (at the We Know London booths). They'll even send it directly to your hotel or to any address in the UK. The device always comes with a return envelop. To return it, just put it in the envelop and drop it in the nearest mailbox. Prices from £6.10 a day.