An example trip in Google Transit from my office to the airport (PDX). View the full size image to see everything more clearly.
Notice how your query can take the form “here to there at this time” – the time factor is nice.
You can click on each trip section to get the familiar little detail balloon to pop up. Each bus/light rail transfer is highlighted with an icon on the map. Walking directions and duration are included, though I’ve noticed that it often tells me to walk diagonally through the middle of a block to get to the nearest bus stop.
You can toggle between driving directions and public transit. It will even calculate the cost of driving vs. transit, and show you how much you’d save.
Not sure if this is using the same data and/or backend as Tri-Met’s own trip planner, but it looks like it.
At any rate, if you’re in the Portland area, you just got an awesome new public transit planning tool. Hopefully this will be made available in other cities soon.
You can find out more on the Google Transit help/FAQ page.