NY's Metro North Railroad announced one "can now pay for the daily parking fee [at train stations] either with one's mobile phone or online while in the comfort of one's car, on the platform, or even on the train."
"As part of a partnership with Parkmobile USA, customers [passengers*] can visit parkmobile.com and sign up for this service for free. Once registered, you really will be able to pay for your parking from anywhere. (You will even be able to extend parking and add time to your stay if necessary!) You can also download a free native mobile app from parkmobile.com or your phone's App Store for the big three smartphone providers: iPhone, Blackberry or Android. (All other smart phone users can bookmark Parkmobile's mobile browser to initiate parking transactions.) 25c fee. "
(from May 2011 "Mileposts")
The same newsletter also announced that train schedules are available via text message through CooCoo.
*Many transit agencies today call their riders "customers" instead of "passengers". For long time riders it's a bit confusing.