While browsing the other day I discovered that there used to be a meetup for London based HN readers[1] that appears to have fizzled out when the organiser moved over to America. This type of thing seems to have been relatively wide-spread in tech hubs at the time[2].
To try and rekindle a local HN readers meetup in London, I have arranged a meetup event here: https://www.meetup.com/london-hacker-news-meetup/events/288139501/
If you are in the London area, feel free to come along and say hi!
[1] http://www.coderholic.com/hacker-news-london-meetup-a-year-on/ [2] https://github.com/antontarasenko/hacker-news-groups