It's occurred to me recently that while intelligent zoning seems to be a critical ingredient of livable cities, perhaps the less draconian invisible hand of informed consumers would be a more effective agent of change.
For example, I'd love to see a service that uses drive time calculations (as mapping sites to) refined by traffic data to evaluate commute time regionally. The user could enter where they work, what time they commute, and perhaps other routine destinations such as school, daycare, family, etc. Then a map of their region could be generated with some sort of visualization of the weekly travel time investment of moving home to any location.
Imagine if travel time investment was translated to height and the map rendered as a 3D terrain. Near work (or between work and the kids' school) would be the lowest point, and mountains would arise around. Low-traffic highways would cut valleys into outlying areas, and highly congested neighborhoods would become peaks. Personally, I'd want to count time spent on a bus or train as low-waste (I can work on a PowerBook while seated) but time spent waiting for a transfer as wasted. This would cause mass transit routes to cut far-reaching grooves.
Add in other factors (school district ratings, tax and crime rates, property values, population density) and you could have a total "stress map". Providing this as metadata to MLS searches would make it easier for home shoppers to make enlightened decisions.