I think I already know the answer due to security concerns, but I'm flying back in to Heathrow next Thursday, a friend is flying out on the Friday and they want to borrow my camera which I have with me. Is there anywhere I could leave it for them to pick up?
The only way I could think of doing it is at the left luggage office. You'd probably have to leave a note that your friend with passport number xyz has got your permission to pick it up, and possibly show them the bag/camera. Short of that I can't think of anything