Donate to help others help a good cause
When I first moved into the Boston area, a priority was finding a civic organization I could volunteer for and make a difference within the community. That ended up being a lot harder than I would've thought: I e-mailed organizations I thought would be a good fit blindly, and often was ignored or informed I was reaching the wrong department, try person X, but person X had left the week before, try again later and maybe ...
You get the idea. Eventually, I tried volunteering for Spare Change News. Since they didn't have control of their own web domain at the time, much less a useful website, that wasn't the easiest challenge either.
Fortunately, Idealist came to the rescue: They have a nice, clean site that allows searching through non-profits for volunteer and even paid positions for those looking for non-profit work. They make tracking down the right contact person, or even just matching your skills with opportunities, much easier.
It's an invaluable resource that helps others help their communities. Recently, however, they've taken a major funding hit because non-profits, like pretty much everyone else, have slowed hiring. Since job placement ads were one of the largest sources of revenue, the site is now turning to the public: Donate $5, $10, or more and help this great organization continue to do good.