This could easily be used as a gimmick, and may, as a result, not even be true (of course, Grist would never do such a thing), but many charities woo donors with double or triple matching gifts, promising that an anonymous donor will match any amount given during a particular time period.  If, in fact, this is true, you could multiply your donation this way by using it to shoehorn money out of a volunteer rich person... :-)

On a side note, Umbra (or anyone else), do you know if there are laws requiring matching gifts to be real?

I like to go with small monthly monetary donations to the larger charities (eg Enviro Defense, ahem Grist, etc), and give resources/time to my local organizations. Here is another idea for your money - check out the website of your local charity (or charities) of choice, because they usually post a "wish list," or call them directly, and find out what they need, and then buy it. For example, our local homeless teen shelter needs toiletries, warm clothes, sleeping bags, books, school supplies, etc. The local animal shelter needs towels, blankets, food, cleaning supplies, etc. You could take that $1,000 bucks (your parents rock!), and buy items directly, so you know exactly where your money went. It would take a little more time, but then you know your money goes directly to those in need. Happy "shopping!"

Hi Emily
My suggestion is maybe that you add to this generous gift by giving a gift yourself...that of your time.  The best way to ensure that your charitable giving is used effectively is to become involved in the local chapter of social services or environmental organization.  You'll have the chance to see how the financial contributions directly affect people and you'll perhaps have the opportunity to decide where the organization targets its resources.  If you are like me, you won't have any regrets about the time you volunteer.
- Jeff

Ok, I had another idea. This one is admittedly more complicated, but meshing the ideas of Jeff and Andrew (and me). Consider hitting up friends, family and coworkers for your own one-year volunteer-a-thon. Here is how it could work: 1. Ask for donations. Tell people that for every $10 you get, you'll volunteer one hour, and donate $5 of your own (a 50% match, from the original $1000). So, if I am doing the math correctly (forgive me, it is Monday, after all), when all is said and done, you'll have $3,000 to donate, plus 100 volunteer hours! Wow, what a win-win-win! Like I said, it is more complicated, but what a way to leverage that $1,000.

"Engineers: Making things extra complicated for the greater good!"

Be aware that Charity Navigator doesn't review organizations with budgets under 1/2 . So if you limit yourself to only those orgs that are passed by them, you're omitting all of the small and local groups. Of course, in the greater scheme of things, these are the groups that probably have the largest impact on land use and that are most starved for funding, because most environmental funding goes to the Inside-the-Beltway DC crowd. The small local groups have the lowest overhead. They just lurch from crisis-to-crisis. That's what made the "Death of Environmentalism" PR campaign to sell what's-their-faces book so funny. The local grassroots groups are as effective as ever, and as starved for resources as ever. Think globablly, act locally.

Umbra happened to mention one of my favorite organizations, the Natural Resources Defense Council (NRDC). I've supported them for years now, and they seem to be a lean & green organization with very effective results. They consist mainly of a highly skilled group of attorneys, scientific experts, and supporting staff who are able to accomplish amazing things, in many cases just by filing lawsuits, but also by negotiating and working with government officials at the local, state, national, and even international levels. You can tell them I sent you.  :-)

Giving to local nonprofits is always best as it keeps the money in your community. Check out sustainability groups or local growers groups or local green, affordable building groups or simple-living groups. I believe these types of nonprofit organizations have the most personal and immediate effect on helping to change behaviors and outcomes in communities.

please do NOT give any money to the NRDC or the Sierra Club and please tell them that you have the money and aren't giving it to them as long as they support total obliteration of hundreds of thousands of acres of fragile desert wilderness to support new faraway utility-owned power plants and power lines on pristine land (and have the nerve to call it "green!!"), when all they would have to do to save the planet from global warming WITHOUT KILLING OFF ENTIRE ECOSYSTEMS is steer all that govt. money and political advocacy towards local, decentralized power generation on previously developed land (rooftop PV, for example) which benefits the planet AND ratepayers.  oh, AND the kennedy's view!!

dennis kucinich is ridiculously ahead of all other candidates on environmental vision if you want to donate politically, and if i had $1,000, i would probably give at least part of it to those modest lending associations which help people in poor areas start small businesses, and part towards water sanitation in the third world.  just my 2 cents.

I only learned about the Center for Biological Diversity a few years ago.  They have singlehandedly forced the US Fish & Wildlife Service and National Marine Fisheries to actually comply with the Endangered Species Act as required by law, prodding those agencies to list and protect many species that otherwise would be ignored (and possibly extinct by now).

The CBD won my enduring love when they uncovered and showed a spotlight on the damning evidence regarding Julie MacDonald and her sleazebag role at Department of Interior in undermining biologists and other scientists within F&WS who are trying to do the right thing.  Dear Julie is now long-gone from DOI, after being forced to resign.  (Probably basking on a beach somewhere, but at least not doing any more damage.)

CBD seems like a small group that accomplishes amazing things.  If endangered species and their disappearing habitat happens to be a priority for you, this seems like a cost-effective group to support.  (And, no, I am not affiliated with CBD in any way ... exept that I now donate to them regularly myself.)  

Consider Kiva.org. No-interest microloans you make to aid third-world development are repaid so that the money can be used again and again. And again.

Most give way too much money to their CEO's and compromise way too much. If you talk to the people in the trenches in your local area, they'll have bitter things to say about WWF and NRDC and sometimes the Sierra Club (I have seen the Sierra Club's Environmental Justice wing and Sierra Student Coalition doing good things, however). If you lived in WV, I'd suggest Ohio Valley Environmental Coalition, the foremost group fighting mountaintop removal coal mining. But I would agree that you're better off dividing it into several gifts, and giving it to small groups fighting for specific things you care about, probably in your own local area.

for people like me who are mathematically disinclined, EFA is a great tool that makes me understand math.