Here are a bunch of ways that young ones -- ideally teens, though some ideas may work well for clever pre-teens, too -- can earn extra cash, excerpted from our spiffy Teens and Their Money area. (Send any teens you know there for a vast array of helpful -- and free -- guidance):

  • Petsitting. When someone in your neighborhood goes on vacation, there's often a pet that needs looking after. Also, with people working longer and longer hours these days, some will pay you to visit their pets during the day and take them for a walk. You might be able to put a small flyer advertising your services at a local pet store, such as Petco (NASDAQ:PETC) or Motley Fool Stock Advisor pick PetSmart (NASDAQ:PETM).

  • Tutoring. Some teens report that they earn anywhere from $5 to $20 per hour tutoring. If you're good at a subject, you may be able to earn money by helping others to understand it.

  • Jobs matching your interests. If you enjoy working with young children, see if any day care centers near you need help. If you like the great outdoors, check with your local parks department. If you like movies or recreation, look into movie theaters or amusement parks.

  • Serve the elderly. Not only might you find work in a nursing home or retirement community, but you might also serve older people in your neighborhood. Many older people can't get around much. They may welcome your services delivering groceries, running errands, or doing odd jobs around their home.

  • Be a computer guru. Many people buy computers and have a lot of trouble setting them up and trying to use them. Even if you have an intermediate familiarity with computers, you might offer your services as a local computer consultant. You can set things up, solve problems, answer questions, teach programs, and show people how to send and organize email, upload digital photos, buy something on, use Instant Messaging, or conduct online searches.

  • Caddy at a golf course. This not only helps you learn more about a sport you might enjoy, it also gives you the chance meet a lot of adults from whom you might learn more about the business world. They could turn out to be valuable connections that help you land other jobs.

  • Delivering newspapers. If you sign up to deliver a lot (which may be more possible in areas with apartment buildings), you can make a good bit of money. Some teens make $100 or $200 per week or more.

  • Use your skills. Think about what you're good at and try to teach others -- adults or children. You might offer piano lessons, horseback riding lessons, or Spanish lessons. Maybe you can juggle and entertain at children's birthday parties. If you play an instrument, perhaps you could play at weddings or other events. If you write, you could try to sell articles to magazines or newspapers.

  • Volunteer! If all else fails, or even as a first choice, consider volunteering. Don't just do the first thing that pops into your mind, though. Be a strategic volunteer. Think of a field or company you'd like to learn more about. If you're really concerned about hunger in the world, volunteer at a food bank. If you're thinking about becoming a doctor (perhaps one who treats the elderly), consider volunteering at a hospital (or a nursing home).

To get your kids interested in saving and investing their money (and perhaps to ensure that you'll be treated to a first-class nursing home one day), consider giving them a copy of our new book, The Motley Fool Investment Guide for Teens: 8 Steps to Having More Money Than Your Parents Ever Dreamed Of. And remember to send them to our corner of Fooldom for teens, too.

By the way, if you'd like to receive several promising stock ideas delivered via email each month, learn more about our suite of investment newsletters (which are offered along with some free research reports). Their performance may surprise you. You can also learn all about brokerages and find one that's right for you in our Broker Center. (Did you know that some well-regarded brokerages are offering commissions as low as $5?)