Google Local is great, but if you live in a big city and aren't the driving sort, or are just visiting, their driving directions are all but useless. Google Transit is attempting to solve that particular problem by giving you travel routes by foot, bus, and train. Right now they only have routes for Portland, Oregon (and are of course promising many more cities soon), but it's still pretty impressive to see in action. Google Transit knows not only the public transit routes but also the schedules, so you can pick your departure time or it'll let you choose between the next four departures for the start of your journey. If Google can deploy this for enough cities and make it as accurate as a good hotel concierge, this could be invaluable to tourists. Be assured that Yahoo! and Microsoft have taken note of Google Transit as well.

P.S. Take note of the URL, yet another in Google's long line of inconsistencies. Why not transit.google.com or local.google.com/transit? (The latter works, but then, oddly enough, so does calendar.google.com/transit.)