Lemme help ya out here, Ryan:
Tube 2 for BlackBerry http://www.visualit.co.uk/Blackberry/BB_Tube2.htm
I would like to request a version for San Francisco -- primarily the MUNI system (all busses, not just trains). All the web images have copyrights attached, nobody has much legal luck creating a handheld map for us.
Official SF Muni maps: http://www.sfmta.com/cms/mmaps/official.htm