You can get directions for driving, walking and public transit where applicable, and now Google is updating its popular maps service to include biking directions across the US. It's not using the same algorithms to get your from A to B as it would with a car or on foot, either. Google's been hard at work tweaking Maps for a while now, and its bike directions will try to steer you clear of high congestion areas or tough hills, as well as keeping you on bike lanes where possible.
The new functionality is already live, and you can go see it for yourself. Google's also made it easy for you to report and give feedback on directions that don't work out so well, or that don't include a bike lane when one is nearby.
All in all, it's a sweet day to be a biker. That is, if the service works better than Google's new automated captioning.