Increasing the number of passengers is probably the most effective way to reduce the ecological impact of a car. You both get more utility out of the energy use by the car itself, but you also reduce the total number of cars on the roads and save everybody else some gas by reducing road congestion.
We've already written a post titled "Which Internet Carpool Service is Right for You?", but it did not include PickupPal. While the company was founded in 2007, it is only in 2008 that the website became accessible to the public.
What's PickupPal? What are its goals?
From their website:
PickupPal's objectives are to reduce carbon emissions, combat road traffic congestion, fight high gas prices and enable people to connect and improve the environment.
At its core, PickupPal is an intelligent route matching system which enables users to easily find like-minded, connected people who are going the same way.
According to the company's website, it currently operates in 106 countries and has 130,877 members (though the actual active member number is probably lower). This means there's a good chance that you area is covered.
How Doe PickupPal Work?
It's actually very simple. You create a profile—for free—to give some information about yourself, and then you can decide to request a ride, offer a ride (for a certain fare), or simply look for rides that are requested and offered in your area to see if anything works with your needs.
The whole concept is not to start going places that are out of your way to pick up people who request rides. Rather, the thinking is that there are so many cars on our roads (about 250,000,000 just in North-America) that someone must be going your way, and you simply share the ride (and help pay for gas/parking).
Here's an example of a search for "New York". You can look at "all results", see only "drivers", or only "passengers". This should give you an idea of what the accounts of registered users of PickupPal look like. But unfortunately if you are in Ontario, Canada, PickupPal might not work quite as well because of certain provincial regulations read more about it here.
You can even watch this slightly idealized video of how a PickupPal ride usually works.
Check out PickupPal's website.