London baby, how do I get a free room?

Actually, I have the free room and two nights off - nows what to do.

I’ll be in London on a seminar and have monday and tuesday night off - I need to find something to do. Suggestions?
No museums unless they’re new (I think it’s probably my 30th visit) and open nights - any shows I should know of?

Right now I’m considering the Ian McKellen and Patrick Stewart performance of Waiting for Godot - I’m not much of a theatregoer, so I figure that Godot will make me one or turn me away forever…

I’ve heard thats very good, can you even still get tickets?

Probably not, but perhaps there’s cancelations and last minute no shows?
If not, there’s always the Boyzone concert…

If you can get a seat, you should go.