Here is the website that I created that mashes Google Maps with BART schedules.
Click on a station on the map and see the arrival time of the next trains leaving from that station.
http://pluralconcepts.com/nextBart
The technologies used:
Google Map API - surprisingly easy to learn and use
Yahoo Query Language (YQL) - very nice tool that lets you perform SQL-like queries on XML
JQuery - my swiss army knife for all things UI-related
