If Facebook defines you by who your friends are, and Twitter by what you’re doing right now, Crowdrise defines you by what you care about. That’s how Edward Norton, speaking at the inaugural Nextwork technology conference, thinks about his new crowdsourced fundraising website. It takes a “fun” approach to raising money – with a tagline like “If you don’t give back, no one will like you,” it’s hard to expect anything less.

‘Each time the cognoscenti try to pin down the limits of technology’s potential, they’re proved wrong in 5 minutes.’

In a conversation with Wired’s Jason Tanz (who was very careful not to anger the award-winning actor lest he turn into an enormous green hulk) Norton described how individuals could use the site to “create multiples.” By leveraging their network of friends and connections, anybody can raise more money than ever possible on their own. Such is the capacity of creative forms of fundraising.

“It’s a chance for an individual, in a self-starting way, to have a robust platform for backing a cause that they care about,” Norton said. “To say, this is my life as defined by how I’m trying to change the world.”

Since its launch in May 2010, Crowdrise has been the platform for some pretty unusual endeavors. Will Ferrell will send you a bottle of suntan lotion featuring himself naked on the label to raise money for cancer survivors. Another women has promised to water-ski around Manhattan to raise funds for better medical care for Iraq veterans.

“We didn’t want this to be a use-and-drop utility,” Norton said. “We want it to be a platform that you use to anchor your activist life.”

But a real activist life involves real relationships. What does Norton think of of those Gladwellian naysayers who grumble over the loss of deep, sustained relationships in exchange for superficial connections and “friends”? Actually, not much.

“Each time the cognoscenti try to pin down the limits of technology’s potential, they’re proved wrong in five minutes,” Norton said. “It’s presumptuous to make that assessment.”

Take Julia, a 12-year-old girl who raised $8,000 for a floating hospital on Lake Tanganyika in Africa because she was too young to volunteer at her own. The hospital – rather surprised by this enterprising pre-teen – has since reached back out to Julia.

“If that’s not a substantive relationship being formed,” Norton said, “I don’t know what is.”

While there have always been grassroots efforts to raise money, online platforms have the potential to eliminate the inefficiencies of other forms of fundraising, which sometimes spend 20-40% on development costs. With Crowdrise, there’s no need to host a celebrity dinner for half a million dollars – most of that money goes directly to the cause.

“The argument can be made that this is zero-cost-based fundraising,” Norton said.

And throughout it all, it needs to be fun.

“It’s important that a new generation of people start to connect with this sort of activity,” he said. “Not cool, but fun – life-expanding, something that pulls on their skills and creativity.”

To start that creative process, you could check out Wired’s own Crowdrise campaign, which will donate money to Khan Academy, an online educational library of free video tutorials. A donation of $34 will even enter you to win an iChat with Norton himself.