Adam Hammes, president and founder of Urban Ambassadors and manager of sustainability at Kum & Go LC, will be the speaker at the May 1 Let's DU Lunch event. The event will take place from 11:30 a.m. to 1 p.m. at the Des Moines Club at Ruan Center, 666 Grand Ave., 34th floor. Registration is $17, and $13 for those age 35 and younger. Click here to register.