Google Maps just got a jaw-droppingly impressive upgrade to its directions functionality. Just watch the YouTube video already:
You have to play with it to believe it. And it works in Europe too, across countries:
And it handles ferries seamlessly:
I have no idea how the algorithm for finding routes does its work so fast, or how address labels get to be displayed on the fly as you drag a destination around, but this bit of AJAX programming is simultaneously technically stunning, useful, and easy to use.