I use public transit every day and rarely drive, unless I'm going out of town. And as much as I love my city, their trip planners are not as helpful as they could be. So where do you go for some bus- and train-hopping advice? You head on over to Google Maps, of course!
GoogleMaps has an awesome public-transportation database that tells you which bus to get. Enter your start and end addresses (or zip codes), select which mode you want (here in SF, you can take Muni, Bart, or Caltrain to get around), and the Google guru will do the rest. Plus it seems pretty reliable, as I've tried it twice for places I've never been before and happily arrived within 10 minutes of the ETA that Google Maps provided. And since Google is racking up the cities that they can map out for you, you should always be able to find your way — and be a bit more earth friendly to boot!