I have been using Metro by Kinevia for years, originally on my trusty Palm PDAs, and more recently on my BB Handsets. It is really, really useful for those of us who travel a lot and I strongly recommend the Metro application
Does anybody know if a version is coming out for the PlayBook?
Metro is a free app that is a guide to Public Transport Systems around the world (I think they have over 400 cities covered by now - April 2012) - it doesn't show you a map, but it creates a table of possible routes, with options for quickest, least changes, etc, etc. For big cities with large and complex tube(metro), tram and bus routes it is a godsend
I've sent them a donation in the past (not much - I think it was c. 10 Euros) - but I cannot find a link to email them with my Metro on PlayBook question