Finding the next bus is as easy as opening Google Maps, though not in Sydney and Melbourne.
If you get around on buses or trains a lot, then a phone app with the latest timetables can be handy.
There are various apps for this purpose (like Tripview for Sydney), but one of the most interesting things about Google's new Transit Navigation Beta for Android phones is that it not only lets you search for buses or trains, and see the timetables, but you can do it all within Google Maps and it will track where you are and tell you when you're approaching your stop.
If you're commuting on the same route every day, this mightn't be so useful, but for tourists or people that don't have a car and rely on public transport to get around everywhere, it's potentially a handy tool.
For now though, people in Sydney can use the service for light rail and monorail, but it won't help you with buses (which we've confirmed with Google). That goes for Melbourne too. The Transit Navigation service is available in Perth and Adelaide.
We checked with Google and a representative told us they didn't have a timeline to give us for when Google Transit might include information about Sydney buses.
For Sydney bus and train users, it looks like TripView is still the tool of choice for now.
[Update: for those wondering, Melbourne isn't listed as one of the places Google Transit is enabled, so our understanding is you won't be able to search for tram details this way either.]