O2 has partnered with Virgin Media to provide free Wifi connectivity to its customers throughout the London Underground train system, affectionately known as the Tube. Virgin Media has hotspots in more than 120 Tube stations and has already partnered with O2 competitors Vodafone and EE, leaving Three as the only major UK carrier to not offer this service to their users.
If you are an O2 customer and wish to take advantage (and really, who wouldn't?!), connect to a Virgin Media hotspot and select O2 from the list of carriers. Then simply fill out the form, including your mobile number, and surf the great expanse that is the internet.
This is a huge benefit to anyone in London with a smartphone, as the Underground is bereft of cellular data coverage. So if you see someone staring blankly in boredom, or trying to get overly chummy with their fellow riders, chances are they' are not some weirdo, they're probably just a Three subscriber.