volunteers building a house (Photo: KidStock; Getty Images)

Everything here only costs a few bucks or takes a few minutes, but the impact? Huge.

1. Train a service pet. A $5 gift to canine assistants.org covers a week of food for a puppy learning to aid people with disabilities.

2. Buy groceries for a needy family. Nearly 50 million Americans are facing hunger; $21 to feedingamer ica.org feeds a family for two weeks.

3. Donate your old phone to cellphonesforsoldiers.com, which recycles them and uses proceeds to buy calling cards for our troops abroad.

4. Restore vision. $50 to unite forsight.org gives surgery to one of the 94 million people who are blinded or visually impaired by cataracts.

5. Rehabilitate women who’ve been trafficked. Senhoa.org hires survivors to make jewelry and helps them safely transition back into society.

6. Provide a kid with peace of mind. Holiday bulbs designed by celebs like Brooklyn Decker support the Child Mind Institute, which researches mental illness in kids ($40, available at bloom ingdales.com).

7. Help more teens in the U.S.graduate. A million drop out each year. Tutor and assist in an at-risk classroom for 10 months with cityyear.org.

8. Keep an infant HIV-free. In Africa, more than 800 babies are born with it daily; $50 to m2m.org teaches an expectant mom to avoid transmission.

9. Donate your wedding gown or veil to brides againstbreastcancer.org. They’ll sell it at a bridal show and help pay for support groups for patients.

10. Comfort the homeless. At projectnightnight.org, $20 provides a blanket, book, and stuffed toy to one of the 334,819 kids in shelters nationwide.

11. Beautify a city park. $15 to tpl.org goes toward playground equipment in a new or renovated green space for boys and girls across the U.S.

12. Ready young mothers. $50 to nursefamilypartnership.org coaches five first-time moms about healthy pregnancies and smart parenting.

13. Save a life in South Sudan. $5 to doc2dock.org ships unused supplies from U.S. hospitals to remote clinics, where shortages threaten lives.

14. Give Internet access to Afghan women. $25 to youngwomenforchange.org donates a desk to the first-ever female-only Web café in Kabul.

15. Prep an animal for its new home. Just $10 to petfinder foundation.com vaccinates four shelter dogs or five cats, keeping them ready for adoption.

16. Invest in health. 17% of American young people are obese; $50 to actionfor
healthykids.org buys PE tools for a class in a struggling district.

17. Inspire a new author. M. Ward and Zooey Deschanel’s holiday album ($11, amazon.com) benefits 826 National, which helps disadvantaged students build writing skills.

18. Stop partner violence. In honor of Yeardley Love, who was killed by an ex-boyfriend, joinonelove.org educates us all to prevent abuse.

19. Pay for a terminally ill child’s getaway. $25 to givekidstheworld.org helps affected families take a vacation to its Florida resort.

20. Volunteer from your desk. Sparked.com asks about your skills and passions, then gives ideas for using your talents to better the world.

21. Fight lung cancer. A donation to lcfamerica.org funds research to predict, detect, and treat the top cancer killer among Americans.

22. Take care of amputees. $300 to brac.net provides a prosthetic arm or leg to a Haitian who lost a limb due to the 2010 earthquake.

23. Prevent illiteracy. Order yourself a new book at better worldbooks.com, and they’ll send one to a needy child in the U.S. or abroad.

24. Raise a roof for a struggling family. Spend a day at one of womenbuild.org’s 27 sites and help put a low-income family into a home.

25. Groom women for government with a gift to the nonpartisan wufpac.org, conservative shepac.com, or liberal emilyslist.org.

26. Keep at-risk youth drug-free. For $25 to deaeducationalfoundation.org, one girl can attend after-school dance classes for 10 weeks.

27. End hunger. Spend $120 on a Feed tote full of gourmet snacks (deandeluca.com), and 15 meals go to kids in Africa, Asia, or the Middle East.

28. Soothe a scared kid. Send a stuffed animal to projectsmile.org; police officers and paramedics will hand them out to trauma victims.

29. Give land to a poverty-stricken woman. For $150, landesa.org secures a plot for a woman in India to live and grow food with her family.

30. Rush in relief when disasters like Hurricane Isaac strike. Teamrubiconusa.org uses your $11 to keep a veteran ready to deploy to crisis areas.

31. Rebuild schools after devastation. Every dollar to happyheartsfund.org, created by former Glamour Woman of the Year Petra Nemcova, does just that around the globe.