The buildings at 320-324 West Geer Street were constructed in 1949, likely intended as multi-tenant rental space from the outset. By 1955, the tenants were:
320: NC State Auto Association, CT Wilson Construction Co., Garrard Realty, and Hilco Co.
324: JA Fargo Carpets and Rugs
320: NC State Motor Association
324: Durham Art Shop Carpets
320: NC State Motor Club
324: Fargo-Hanna Oriental and Domestic Rugs
The buildings currently house an array of interesting businesses. These include El Kilombo, a self-described "community space and radical bookstore" and the Vivala Raza Market.
Would that we had such a diversity of interesting businesses/tenants at such density through much more of downtown, but I suspect that rents are typically too high or buildings too absent to allow this to occur on a wider scale.