The excellent HSR and Google Maps partnership to provide trip planning is disabled until Friday, May 8, 2009.
After Friday, try it if you haven't yet. It gives you the next three available trips to your destination including walking, waiting/transfer times, and allows you to choose the day and time of arrival or departure.
The only problem I've had with it is seasonal routes show up as year round (ex. Rock Gardens), but otherwise a very excellent tool. (It should make the HSR's horrible online trip destination tool obsolete.)