The user interface design is interesting as they use on the phone typical phone interaction (basically dialing an number) and keep the interaction with the ticket machine the same (except there is no need to insert coins) as it was before. But looking at some work we did in the PERCI project with DoCoMo in Munich we can tell that this is just the initial state of physical mobile interaction  – it can be expected that this will become more common!
 Broll, G., Siorpaes, S., Rukzio, E., Paolucci, M., Hamard, J., Wagner, M., and Schmidt, A. 2007. Supporting Mobile Service Usage through Physical Mobile Interaction. In Proceedings of the Fifth IEEE international Conference on Pervasive Computing and Communications (March 19 - 23, 2007). PERCOM. IEEE Computer Society, Washington, DC, 262-271. DOI= http://dx.doi.org/10.1109/PERCOM.2007.35