By Emma Haak

Giving back doesn't have to mean giving up every weekend.

1-5 Minutes

• Want to save a life? Sign up for your state's donation registry through OrganDonor.gov.

• Use Goodsearch.com's Yahoo!-powered search engine every time you browse the Web, and you'll automatically give to a nonprofit like the American Cancer Society.

• Donate hotel loyalty points and airline miles on Wish.org to help the Make-A-Wish Foundation grant requests to children with life-threatening conditions.

• Play crossword puzzles at Charitii.com, and the site's sponsors will make a contribution to one of five charities for each correct answer.

30 Minutes

• Re-gift the blender and other household goods you didn't ask for to a local firehouse (call ahead), so first responders can make their living quarters feel like home.

• Mail a letter of appreciation to a member of the military through AMillionThanks.org.

• Gather your old cell phones and laptops for donation to the National Coalition Against Domestic Violence, which will resell them to fund outreach programs.

• Download the Charity Miles app and go for a run, walk, or bike ride; you can earn up to 25 cents per mile for nonprofits, including Autism Speaks and Stand Up to Cancer.

1-2 Hours

• Bring a little TLC to neglected public spaces in your town by organizing volunteers to pick up garbage. Use social media to spread the word about your "Trash Mob."

• Explain why Horton hears a Who, as a United Way volunteer reader, mentor, or tutor for elementary schoolchildren.

• Assemble gift bags for Cheerful Givers, a nonprofit that distributes birthday presents to kids at food pantries and shelters.

• Give a pint of blood. Make an appointment at RedCrossBlood.org.

4 Hours

• Head to a soup kitchen, where you can greet and seat guests, bus tables, wash dishes, or prepare and serve meals. Look for one at FoodPantries.org.

• Run errands for the elderly or shuttle them to and from doctors' appointments. Find a neighborhood senior center through the National Council on Aging.

• Help the Salvation Army staff sort through donated clothing. (They receive more than 300 million pounds a year.) Find a branch at SalvationArmy.com.

• Round up a few funny or uplifting DVDs and host a family movie night at your local Ronald McDonald House. (There are 176 locations throughout the country.)

4+ Hours

• Show off your fashion sense by helping disadvantaged women choose job-interview outfits through Dress for Success.

• Go to Habitat.org to sign up for a shift with Habitat for Humanity, which needs volunteers of all skill levels to build homes for low-income families.

• Host a board game party for adults with developmental disabilities at a group home in your area. Find one through the advocacy organization The Arc.

• Help the homeless find places to get warm. Check Volunteers of America for opportunities at shelters in your town.

