Google Transit Now In Google Maps
If you plot driving directions between Norwalk, California and Orange County, California, you should see an option on the left for “Directions: Drive There – Take Public Transit.” Clicking on “Take Public Transit” will plot Google Transit data within maps.
After you click on the transit link, you are given various ways to take public transportation between the two locations. Here is a picture of that in action:
Here is an embedded map: