As gas prices continue to march toward $4 a gallon, cars on display this weekend at the Portland International Auto Show offer a range of new, fuel-efficient models that not only are easy on the environment but also on the wallet.

The 2012 vehicles include dozens of fuel-efficient cars that get 35 miles or more per gallon; high-end hybrids; all-electric cars that travel 80 to 100 miles between charges; and even a car powered by natural gas.

New Year's resolutions are easy to break. But if one of your resolutions is to live a greener life, here are 10 simple ways to make a real change:

1. Go cold.

Rather than washing your laundry in warm or hot water, wash every load in cold water. Your clothes will get just as clean, and you'll save energy. According to the Department of Energy, washing in cold water can save consumers up to 80 percent of energy per load, which translates to up to $100 per year.

2. Pitch the paper.

For birdwatchers like me, one of the highlights of the holiday season is the National Audubon Society's annual Christmas Bird Count. It's a chance for experienced birders to monitor the health of their local avian community, but it's also an opportunity for would-be birdwatchers to get a taste of a fascinating hobby while participating in one of the world's oldest "crowd science" efforts.

In this 112-year-old tradition -- started as an alternative to Christmas bird-shooting competitions -- groups of bird lovers head out one day between Dec. 14 and Jan. 5 to record the number of species and the number of birds they see. Last year more than 60,000 people tallied more than 61 million birds, according to the Audubon Society.

My back ached, my feet hurt, and the kitchen was a disaster. But after hours of peeling, coring, mixing and pouring, the jars of caramel-colored apple pie filling emerging from the boiling depths of the canner made it all worthwhile.

I taught myself how to can nearly 10 years ago and have been teaching other people the throw-back art of "putting up" for the past few years. Now it doesn't feel like fall until I've teamed up with friends or family members to put something we've canned into the pantry. During last weekend's canning marathon, my sister, brother-in-law, two nieces and I transformed 60 pounds of apples into three dozen quarts of apple pie filing and applesauce.

Yes, we should all live more eco-friendly lives. But, as my children have taught me, sometimes it's easier to do the things you should do when the possibility of a prize awaits.

Good news: Several organizations are hosting eco-themed contests, so going green has never been so tempting. Here are some of the latest environmental contests:

You know all the food scraps, grass clippings and other organic materials you throw out each week? Stop. By saving those materials as compost, you'll never need to buy fertilizers or bags of potting soil again, and you'll have healthier plants than ever before. Even better, you'll be doing your part to reduce the volume of waste tossed into the landfills.

"Landfills have limited space, so why fill them up with valuable materials that you can use at home instead?" says Lars Hundley, a certified master composter in Dallas who runs CompostGuide.com. "On a macro level, composting reduces the costs involved with hauling around organic waste in trucks and throwing it into landfills instead of using it on-site and turning it into rich, fertile material that you can use in your yard. On an individual level, you can save money buying fertilizers and bagged compost by simply making your own with the materials you already have."

You've stopped using plastic grocery bags and started bringing your own reusable bags to the market. Now, here are five easy ways to eliminate even more plastic from your life:

1. Shower curtains. Rather than buying a plastic shower curtain, opt for one made of fabric, says Kris Bordessa, the blogger behind Attainable Sustainable. Fabric shower curtains are easier to wash and reuse, and they don't emit the toxic fumes that PVC curtains do. Go even further: Eliminate the plastic liner, as well. Bordessa says she doesn't use one and never has splashing problems.

Patti Booterbaugh's Italian sojourn was not nearly as glamorous as Julia Roberts' foray in Eat, Pray, Love. There was no wine tasting, no slurping up pasta at a little bistro in Rome and definitely no basking under the Tuscan sun.

Instead Booterbaugh spent two months on two different farms, where she pulled weeds, picked vegetables and helped prepare meals. She loved it.

When Aaron Pratt began selling his handmade rain barrels on eBay in 2001, he was the only one doing it. Today, there are almost 400 different rain barrels for sale on the site. They're also available at your local discount store or natural grocery.

Why the explosion in manufacturing rain barrels? Pratt, owner of Aaron's Rain Barrels in Leominster, Mass., says people have figured out it's an easy, inexpensive way to go green.

Scott Hamlin doesn't believe in waste.

To prove it, in 2009, Hamlin co-founded the Portland, Ore.-based Looptworks, an online-apparel company that makes limited-edition jackets, hoodies, skirts, shirts and graphic tees. But here's the twist: All of Looptworks' products are made from (gasp!) "upcycled," or excess manufacturing fabric and materials.