I like to attend hack camps which are often up in 'that London', so it calls for an overnight stay. The pain can be lessened with some lightweight camping kit.
Don't count on there being soft things to sleep on, darkness or quiet. I've also been known to take my mega cheap Millets dome tent. They stand up without pegs and don't even need to be waterproof. I plan to be super-geeky and kit it out with a pico projector or LEDs.