What it is
No matter what we do with regards to using better technology to get around, it is still unlikely to be as good as simply driving less. We are not suggesting running your drivers' license through a shredder, but making a conscious effort to drive less can have a number of positive impacts. When you need to get somewhere, there are a number of ways to do it. Only one of these methods involves getting into your car. Driving less can include anything from taking public transport to walking or biking to carpooling to simply making more efficient trips to the store.
We are not suggesting running your drivers' license through a shredder
Public transportation is a means of getting a lot of people from one place to another in an efficient manner through rail, bus, or plane. The reason why we fly on commercial airplanes is because it is more efficient and less expensive to do so than to have everyone fly on their own. This idea can be extended in many places to buses and trains. Sure, it is not always as convenient as getting in your own car, but with proper planning, it can lower your negative impact on the world and also save you money.
A similar solution is carpooling. In short, carpooling creates your own miniature public transport system that is not as efficient, but much more convenient. Obviously, the more people the better. This not only saves on emissions, but also on things such as fuel, toll, parking, and car maintenance costs. It can also save you time by allowing you to use High Occupancy Vehicle (HOV) lanes and sometimes giving you preferred parking.
Even better than these is walking or biking to where you need to go. Between a backpack, basket, or even trailer, biking can be used for efficient and essentially energy-free method of running errands or getting to work. Even walking can be used to run errands within a couple miles of your home. These obviously take a little more time, but if you live in an area with heavy traffic, you could be surprised at how little extra time it takes to walk or bike a short distance. These methods can also be combined with public transport to travel reasonably long distances.
Finally, if none of these situations will work for you for a particular trip, you can work to make efficient trips by running all of your errands at once and in a route that minimizes fuel consumption. This can involve things such as declaring a number of days a week where you won't run errands, planning household needs such as groceries in advance, and combining errands with times you are already out of the house driving around.