Jerry Greenfield (of Ben & Jerry) and Julius Walls (CEO of Greyston Bakery) are in town doing a campus tour of NYU and Columbia to talk to tomorrow's business leaders about social entrepreneurship. The Greyston Foundation donates all profits to local charities, including community gardens, affordable housing, job training and childcare programs. Which is all terrific! But let's talk about the sundaes: The idealistic duo will be serving free ice cream and brownie sundaes at the Whole Foods Tribeca TODAY from 12:30 to 2:00 p.m., and then from 4:30 to 5:30 p.m. at Whole Foods Bowery. Later they'll visit the campuses to inspire business students to start socially responsible companies that, hopefully, also give out free ice cream.