The “Iowa Downtown Summit” starts in Grinnell today (Tuesday). Bill Menner, director of “Grinnell Renaissance,” says it’s the annual meeting for people who do what he does. He says participants run downtown organizations, advocate for them, live there or own downtown businesses, and believe Iowa’s downtown areas are vital places for business. About 350 people from around the state are expected today in Grinnell. Two of the country’s top retail consultants are coming: a woman who runs the national Main Street Center in Washington D.C. and Iowa State University economist Paul Lasley. Menner says the summit is sponsored by Iowa’s Department of Economic Development and the Downtown Resource Center. With the theme “Downtown — a Smart Place for Business,” he says it’s a look at “smart” ways of enhancing business like technological enhancements, using the Internet, strategies that enhance economic-development opportunities.