Check Traffic Reports Before You Leave
Rush hour traffic is, in my humble opinion, the worst thing in the entire universe. Spending hours in the car desperately trying to get home after working a full day is someone's horrible idea of a joke. The environment suffers right along side us as we creep our way through commuter hell. All those idling cars really do a number on the air quality, too.
In addition, the gas isn't even really being used to its full potential. It's troublesome enough that we have to use CO2-emitting fuel to get around in our society, but it's ten times worse when we just waste that pricey gasoline sitting, going nowhere, in congested rush hour traffic.
A simple way to waste less gas while commuting is by checking your local traffic reports online. You'll be able to get up-to-the-minute information about your streets and avoid areas of ridiculous congestion and settle for less preposterous amounts of congestion. Traffic.com is a good place to find this information. You should be able to find local sources of this info as well.
You might have to drive a little out of your way in some cases, but a car in motion isn't as damaging as an idling car. It's also better for the car to not let it idle. You win twice, and hopefully a third time when you arrive sooner than usual.