A new site uses the Web to help you raise money for charity.

Remember the old method of passing a sign-up sheet around the office cubicles and asking your colleagues to pledge a few dollars to your Walk for [insert cause here]? Now there’s a way to turbo-charge that. It’s called Crowdrise, a new online platform that allows volunteers to seek sponsorships for their volunteering by leveraging the power of the Web. Crowdrise’s founder, actor Ed Norton, should know: he helped the Maasai Conservation Wilderness Trust raise more than $1 million in two months by running the New York City Marathon and crowdsourcing donations. He based the model on his success.

On Crowdrise you can build your own fundraising page, make donations, and join teams to spread the word about your charitable cause along the network. (“It’s like communism but more fun!” the site teases in its signature irreverent voice.) So far, the site has attracted celebrities—including Seth Rogen, Will Ferrell, and Kristen Bell— and it recently partnered with HandsOn Network, the volunteer arm of Points of Light Institute, which delivers 30 million hours of volunteer service each year (which it values at $626 million). HandsOn will use Crowdrise’s online tools to raise money and awareness for its volunteers.

Crowdrise members get the chance to win prizes like t-shirts, iPads, and cash for their charities. They also earn points when the Crowdrise community votes for them, and for the money they raise from supporters; top earners get titles “tsar” and “DJ.” (“DJs get to make fun of everyone except for Sirs and Dames, and if we ever have a Crowdrise Airlines, DJs will always get to fly first class.”) In the end, though, the real incentive is the opportunity to give and raise money, easily. Or, as Crowdsource’s slogan puts it, “If you don’t give back, no one will like you.”