Some time back I noticed that Google Maps has now started provided driving directions for Bangalore (and some other Indian cities). This is a very useful feature if you live in Bangalore and wish to avoid its awful traffic as much as possible. It's invaluable if you are new to the city and trying to figure your way around it.
For example, here is the route it suggests you take if you wish to go directly upon arrival at the Bangalore central railway station to Brigade Road:
The route calculator does seem to take one-way roads into account, though not the usual traffic-density or the condition of the roads involved. For example, even though J. C. Road is a wide arterial road, it should be avoided around office hours on a weekday if you do not fancy being stuck in a jam or crawling traffic. As another example, the work for building the Metro rail network has severely disrupted the traffic on many a road in Bangalore. To be fair, these parameters are quite variable and perhaps difficult to keep up-to-date.
It's fun to discover that some of your pet routes for going to different places in the city can be improved upon by making them shorter, some times in surprising ways. It does not always suggest the shortest path though - you can drag the suggested route around a bit to see if there's a slightly shorter path available.
It would be nice if Google provided this feature for GPS-enabled smart-phones connected via GPRS and then collaborate with cellular network providers to use the density of mobile phones in a cell as a decent approximation to the traffic congestion in that area in order to dynamically suggest alternate routes to you.
Update (2009-12-18): They now provide landmark-based navigation for Bangalore. This is pretty cool and quite useful.