Living on a farm, I don't travel all that much. The place doesn't take care of itself, and the schedule of chores isn't real flexible -- certainly not to the extent of a day or more. Still, my duties at Greenback do take me on the road (at least figuratively) from time to time. More often, these days, that "road" has rails.
With the price of gas being what it is (who would have thought $3.90 would seem cheap?), virtue and value are both spelled "AMTRAK". Thus, whenever practicable, I ride the train. Sometimes (most of the time) it takes longer than driving, but then I can get stuff done on the train that I probably shouldn't do (like reading) while I'm at the wheel. Generally it takes longer than flying, but it doesn't seem much longer, because the seats are wider and farther apart, and the luggage racks are less crowded. Also, there's no need to go through Checkpoint Charlie just to get to Secaucus.
Like most business travelers, I make my arrangements online. I have to get Amtrak tickets at their site, but for hotels and (when necessary) car rental or plane tickets I use Travelocity or Expedia. Recently, though, I learned not to go to either of those services directly.
A short detour ...
One of my favorite non-profits is Engineers Without Borders. Using mostly student (and other volunteer) labor, they implement civil and other engineering projects in developing countries at little or no cost to the recipients. Their projects save lives, improve lives, and are heavily imbued with the concept that sustainability is tied to locality and efficiency. If you want to learn to solve problems without throwing massive quantities of electricity at them, there's nothing like the near-complete absence of electricity to open your mind to other alternatives. Constraints can be liberating, at least in terms of thinking.
Anyways, EWB sends students oversees to do good work. Of course, most of the time, that means flying them there. Flying causes lots of GHG emissions. Not a good thing. So, EWB tries to offset those emissions. But offsetting costs money, and EWB is a grassroots non-profit with limited funds available. Happily, I can help.
Rather than going to Travelocity (or Expedia, or Hotels.com, or Priceline, or ...) directly, I go to www.GreenTravelPartners.com/ewb.htm . I then click through to the travel service I want to use, and everything's just like normal. Everything except the cashflow. Travelocity (for example) takes a small fee on every trip booked through their service. If I go to Travelocity directly, they keep that fee as income. If I go to GreenTravelPartners, however, half of the fee goes to EWB, who use the income to purchase offsets for their own travel emissions.
So, traveling by train allows me to contribute to both economic and ecological sustainability. When that's not practical, arranging my travel through GreenTravelPartners contributes to both social and ecological sustainability. Neither of them perfect solutions, but both far better than not.
The perfect solution? Actually, that would be staying home in the first place. But that's just me.