New York (CNN) -- Don't think raising money for nonprofits is an overly sexy undertaking? Don't tell actor and activist Edward Norton.
"Crowdrise is pretty much the most fun you can have making a difference without taking any illegal substances," Norton said about the online initiative he announced Tuesday at the Mashable Media Summit.
The summit, co-sponsored by CNN.com, is part of Internet Week New York.
At Crowdrise.com, Norton and his colleagues have set up what they hope will become a crowdsourced community of volunteers and fundraisers to support a host of causes -- from global environmental threats to local clean-up projects.
Norton, a longtime activist who's been involved in issues ranging from environmental protection to affordable housing, took his first plunge into online fundraising last year.
He ran the New York City Marathon and, in the months leading up to it, took to Twitter and a website to raise pledges that would go to the Maasai Wilderness Conservation Fund -- a charity working for sustainable development in eastern Africa.
In that effort, Norton and other supporters offered gifts and other incentives to inspire giving.
"When we came out the back side of it, we definitely felt it was like a beta test on how to create a good tool for anybody to do the same thing we were doing," Norton told CNN. "We took a lot of lessons we learned from the Maasai run and created something that anybody could use."
Norton, whose credits include "Fight Club" and "The Incredible Hulk," said his group wanted Crowdrise to be fun and easy to use.
It lets anyone create a profile, register a cause, ask for donations then communicate with supporters in creative ways.
Nonprofits already using the site include both large and small organizations.
"Crowdrise is the only website that makes it so easy to turn our base of passionate grassroots advocates into a base of passionate fundraisers," said Danielle Murray, associate director of the Conservation Lands Foundation.