Spring-going-on-summer seems the perfect time to start composting, if you aren't already. If you keep your own plants or garden, you'll save money, avoid the need for chemicals, probably have a more robust harvest, and will definitely cut down an unbelievable amount on how much trash you produce. If you don't garden at home, how about joining a community garden and using your compost to grow veggies there? You can also get a machine to do it for you, or in certain cities, you can bring your food waste to the farmer's market.
And the more things you dump in the compost bin, the more you'll keep out of your trash—and the landfill, which means less energy will be used for transporting waste, and less methane will be created at already-overcrowded landfills.
If you're just starting out, Planet Green and Treehugger have the basics covered, including the scoop on worms. Sami has some helpful advice if you experience a case of the smellies: add cardboard to your compost, which will help balance out the nitrogen-carbon ratio. He also has ideas for how to built your own compost tumbler.
There are so many earth- and wallet-friendly reasons to compost, it really doesn't make sense not to.