I am just back from the trip in North-Western part of Russia. There we had to transport our bikes on suburban electric trains, where there is very little space for bicycles, the way local cyclists do it:
Bikes are hooked to the shelves with the saddles and handlebars leaning against the walls/windows. Turns out it is really stable.
This is how it works where it is really too tight, ferry boat (photo was taken from the local biking club site, velopiter.spb.ru)
Any more creative ways how to transport your bike?
PS. Not sure which (sub)forum fits for this thread, touring seems appropriate.