Today I went to see Glass Body. I liked it, though I didn't really understand some of it. If you like this sort of thing, you should go and see it too. Entry is free. (Time Out review, from a previous run at a different hospital.)
This is the final week — remaining performances are Wednesday 21st: 2pm and 4pm; Thursday 22nd: 1.30pm, 4pm, and 6.30pm; Friday 23rd: 2pm, 4pm, and 7pm; and Saturday 24th: 2pm, 4pm, and 7pm. The venue is Atrium 1 of Guy's Hospital; you get there by going over the footbridge from London Bridge station, following the corridor round, going down to the ground floor in the lift (I looked for stairs but couldn't find any), and it's on your left as you exit the lift.
(There's a game, too, though it's not particularly great.)