A somewhat interesting idea...
At J's flat last night, on inviting J's flatmate Martin to the pub
M: Tempting, but I can't drink alcohol tonight. I'm going to be part of some medical research tomorrow.
D: What are they going to do to you?
M: Stick a tube up my nose down to my stomach. Then I have to carry a box around with me that takes various readings for a day.
D: What for?
M: Don't know, I think for giving doses of something or other to patients. I'm healthy though so I'm their 'normal.'
D: How much do you get for your efforts?
M: A hundred pounds.
D: That's not a bad rate.
M: Getting my wisdom teeth pulled out will pay more though. I've got to have them out anyway. It's either a general anaesthetic at the dentist's with me paying or a local at these guys' and they give me four hundred per tooth.
D: (Jokingly) Is this to test your pain threshold or something?
M: Urm... yeah.
D: You're not normal.