You may have heard of Black Friday and Cyber Monday. There’s another day you might want to know about: Giving Tuesday.

The idea is pretty straightforward. On the Tuesday after Thanksgiving, shoppers take a break from their gift-buying and donate what they can to charity. You can go to the Giving Tuesday Web site and find thousands of groups to support, from a local home for a neglected children to a disaster-relief program in the Philippines. Melinda and I posted our own list of four great organizations, but there are many others that are just as deserving.

Giving Tuesday is part of a larger trend that I find very encouraging: Technology is creating the opportunity to make philanthropy both more efficient and more effective.

Just as online technology is helping business reach millions of new potential customers in a more targeted way, it’s also helping non-profits reach a huge pool of potential new donors. Suppose you’re a small organization that serves meals to homeless people. In the past, you would’ve had almost no chance of getting promoted by a global organization like the U.N. Foundation (which is one of the Giving Tuesday partners) or attention from a celebrity with a big Twitter following. But by joining Giving Tuesday, you can get all these things, at essentially no cost, which boosts your exposure and the odds that you’ll connect with someone who wants to support you.

DonorsChoose.org and Catapult—where Melinda has curated a list of her favorite projects—are two other sites that are helping non-profits connect with new donors. Charity: water lets donors host their own fundraising campaign (like a bake sale or a marathon) and then learn in detail about the projects they’re funding.

The spread of online information isn’t just good for charities. It’s also good for donors. You can go to a site like Charity Navigator, which evaluates non-profits on their financial health as well as the amount of information they share about their work. GreatNonprofits is similar but also lets people who donate or get services write about their experience. Charities crave this kind of feedback, so it’s terrific that technology is finally helping them get it.

Of course, the Internet has not suddenly solved every problem in philanthropy. For example, while it’s great that donors can go online and find out about an organization’s overhead costs, what about its results? How do they compare to other groups doing similar work? Some of the ratings sites plan to try to answer these questions, which is good news. At the same time, non-profits shouldn’t be forced to divert too much of their time and money into filling out reports. It’s a tricky balance and we shouldn’t go overboard.

But the opportunities are growing to connect with donors and make philanthropy even more effective. If you run a non-profit, I’d encourage you to make the most of these opportunities. If you’re a donor, I hope you’ll support organizations that are transparent and effective. You may have to spend a few extra minutes doing research, but the more you know, the more impact your dollars will have. You can also use the ratings sites to help charities improve your experience as a donor. If their Web site made it especially easy to give, let them know. But if they made you regret it by bombarding you with spam and junk mail, let them know that too.

I often talk about the need for philanthropy to target our greatest needs and spark long-lasting change. Effective philanthropy is no longer the sole province of big foundations that employ teams of experts. Anyone with an Internet connection, a few dollars to give, and the time to do a little digging can become a more-informed donor. These days, effective philanthropy is for everyone.