OK, we're off on holiday this week, and DS hasn't been potty trained too long. In fact, rather annoyingly, he had a relapse last week, where he got through every pair of trousers he had at nursery... 
Anyway, the trip consists of a 4 hour train journey, and a 4 hour flight. Now, obviously, there'll be toilets available on the plane, and on 2 of the four trains (one of the trains is a tube, the other is a half hour journey and has no toilets - I know this from doing this length of the journey several times a month) So, to save too many accidents/embarrassments, WIBU to put DS in pull ups until we got to our destination? Just to be on the safe side? One day won't hurt, right?