The Wi-Fi network went live last June ahead of the London 2012 Olympics, but has steadily taken on more of the London Underground since that date. Data access on the tube has also taken in more operators than just owners Virgin Media too. But not O2.Until now that is, with O2 finally confirming to its customers that it will be getting a piece of the action. We say 'now', but what we really mean is 22 July, joining Virgin Media, Vodafone and EE customers in having access to the network as they travel and commute. No sign of Three yet, but peer pressure might make that final move inevitable. If not, £2 per day will be the price for Three customers.Of course, there's no access on the trains, the continuous connection is on the platforms and within the stations. So make sure you don't hit 'send' just after you hurl yourself into that packed carriage.It's good news for O2 customers after recently losing access to BT Openzone hotspots. Although as that turned out, there were 'only' 65,000 hotspots available to O2 via BT out of the four million or so in action.