How can I meet people while traveling in the UK

I'm taking a trip to the UK next week. I am looking forward to visiting London and seeing a lot of things like the British Museum and the Victoria and Albert that I've wanted to see for a long time. Also taking side trips to such places as Bath to see historical sites.

However, I have this vision of spending two weeks kind of bopping around from museum to museum by myself having occasional desultory conversations with other tourists and then retiring to my hotel room to brood in solitude. So you know, that's not too great.

I would like to plan to attend some social events in the evenings to get a chance to interact with local people because that's how you really learn what a place is all about.

I'm looking at Meetup.com and Facebook, and I'm having trouble finding things that relate to my interests.

At home what I like to do is go to social drawing events like Dr Sketchy's Anti-Art School. I also go to a lot of comic conventions and stuff like that.

Here's an example on an event that's the type I like to attend...

http://originaldrinkanddraw.deviantart.com

OK, so I'm into comics and drawing. Anyone know of anything related to that?

But also I'd be down for anything where people are cool and hanging out in a relaxed, informal social situation.

This is a good example of the type of thing that would be great...

http://www.cultureseekers.org/events/62141432/?eventId=62141432&action=detail

More things like that would be excellent.

They have these things around here where people just get together in a cafe and play board games. But when I looked for that in London all I came up with was weird new-age stuff and pickup artist meetups, which isn't my scene.

So I'm kind of having trouble finding what I'm looking for here. Any help or suggestions would be greatly appreciated.