(MoneyWatch) Over 1,200 students attended the Clinton Global Initiative University event this weekend at Washington University in St. Louis to "make a difference." Former President Bill Clinton brought a number of power hitters together to discuss education, environment and climate change, peace and human rights, poverty alleviation and public health.

The headliner was Jack Dorsey, the inventor of Twitter and Square. "He's from St. Louis, we're very proud (of him). For our students and the community, this session will be very inspiring," said Washington University Chancellor Mark Wrighton.

Dorsey knows a thing or two about bringing an idea to reality.

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Here's CBS News senior producer Lulu Chiang's conversation with Dorsey (edited for length and clarity):

LULU CHIANG: Jack, you tweeted "Speaking tonight at @CGIU's opening plenary on entrepreneurship. (Tweet your questions with #CGIU for President Clinton to ask live on stage.)". What are you going to tell the students about entrepreneurship?

JACK DORSEY: How to start, that's the hardest thing to do. It's about taking risks, whether you're starting your business or work in an organization, whatever charity or cause. It's about the attitude of strong purpose and conviction.

LC: What's your appetite for risk?

JD: Extremely high.

LC: Do you consider yourself a serial entrepreneur, first inventing Twitter and then coming up with Square.

JD: I don't consider myself serial anything.

LC: Square really changes how money changes hands?

JD: Square allows people to receive credit card payments through a tiny device plugged in to their smartphone or PC. It certainly makes transactions much easier, revolutionizes how money changes hands from person to person.

It's about having that idea and the execution, and then it's yours for the taking. It's not about doing one thing after another.

LC: How did the idea "Square" come about?

JD: Square -- it was a pretty simple start. Co-founder (Jim McKelvey) also a St. Louis native wasn't able to sell glass art because he didn't accept credit cards (McKelvey was unable to process a $2,000 transaction). We took a month and thought about how to enable him to make transactions, came up with this device. It worked and we showed it to people.

Square charges a transaction fee of 2.75 percent. It's unheard of because no one has done that before.

LC: You can take this and perhaps use it (the field of) public health?

JD: Most surprising facts, it takes doctors and nurses 6 months to a year to get money from treatment. It goes into the insurance channels. They're (doctors) using it for house calls and get their money the next business morning. They have more time to focus on the patients.

It's the little things enabling people to accept money, dramatically impact on people's lives.

LC: Is Square a global phenomenon?

JD: We think this is a global thing, something that resonates around the world -- not just in the U.S. or San Francisco thing. Small, local merchants (around the world) can accept credit cards. Merchants can do transactions if they had an iPad (or smartphone device).

LC: What do you tell the students out there... that wanna be like Jack?

JD: Don't try to be like me. The most important thing is to find own path. Everyone has a completely different perspective.

You have to get started, get the idea out of your head by painting, drawing or coding it. You need to get feedback from other people. Starting is the hardest thing. You can do the same thing within the company your work for or with your own idea. Write it down and speak up and have conviction. Confidence.

Dorsey is the very essence of this conference, to "make a difference". In Dorsey's playbook, the way to make a difference is to have an idea, speak up, take a risk and execute. And you have to strong conviction and confidence too to see it through. "Our students have the opportunity to participate in a conference, learn how do take these ideas and do something with them. Not just coming up with good ideas and but converting these ideas to action," said Wrighton.

Whether you use Twitter or not you have to admit, he's made a difference, adding a new meaning to the word "tweet."

Merriam-Webster's definition of "tweet":

1. a chirping note

2. a post made on the Twitter online message service