Boy, I hate seeing everyone else getting these wonderful new toys to play with while we in South Africa have to sit back and be patient. Google, just open that SA office already so we can get to experience more of your wonderful products once and for all!
I doubt very many people heard of Google Transit, but that's because it was in Labs. This month all that changes as Transit has graduated! It's now fully incorporated into Google Maps. So, what does it do? In the past, when querying directions on Maps you got driving (or swimming!) directions such as these. If you go to that page you'll notice a new option to "Take Public Transit". Click and it and you should get this view as shown below.
If you view the full page you will see that it gives you step-by-step directions, providing departure and arrival times as well as alternate routes. It even gives you the fare of the journey and compares it to the estimated driving cost to compare to.
Coverage is still very limited, but remember this is still a new product and requires a lot of data. I see though that Google have made available a Google Transit Feed Specification. Now I know Google are known for their open APIs as well as getting others to do their work for them, but I find this amazing and would be excellent if it works! They're basically telling agencies that run public transportation that if they want their schedules included into the Transit system, then they have to transform their data into the format specified by Google. You gotta love these guys for their courage!
One thing they could really improve on is their walking directions. Currently they just plonk straight lines, however, this could result in a longer route if the walking line goes across a river, for example. They even mention this in one of their help answers, so they might end up adding this eventually. I imagine that most maps data defines pedestrian roads, so I don't foresee it being too difficult to add.
I love how they fail to update their FAQ! Just look at the following answer from here:
6. Why isn't this product a part of Google Maps?
Google Transit Trip Planner is currently a Google Labs product. We haven't integrated it with Google Maps because we wanted to develop the product further by learning, through user feedback, how people really use public transportation data, and thus how Google Transit can be improved to be as useful as possible.