I just found out the startling news that (if you work at a Greater London school, if you book in advance, and you can persuade them your destination is somewhere cultural, but not sports or leisure related, if you travel between 9.30 and 4pm, if you have one teacher per 20 students) you can order free bus/train/tube/DLR tickets online to get you where you want to go to from Transport For London.
Usually, we end up fiddling the child rates on the tube, and I can't be bothered to wait the five weeks it takes to claim it back from the borough so just pay myself.
Yippee - I'd best get me writing some of the seven page risk assessment plans required to set a single foot outside the building. 'The Trench Experience' here we come.