Popular warm-weather treat in the Baltimore area. A snowball is identical in composition to the snow cone familiar around most of North America, but the ice and syrup reside in a regular cup, rather than the soggy-prone, unrestable, Coney Islandesqe paper cones that inhibit snow cone enjoyment elsewhere.
Snowballs are usually sold at small, roadside stands, and occasionally out of an entrepreneur's freezer-equipped truck. It's a good business while it lasts - my brother paid most of his law school tuition by driving around the city's neighborhoods in the summer and dispensing snowballs to the eagerly waiting locals. The customer can choose from several cup sizes and a (usually) wide variety of flavors.
Flavoring is provided by an array of brightly and unnaturally colored sugar syrups. A snowball is usually a one-flavor, one-color deal, but for a few cents extra most vendors will honor a request for a combination of two or more. The bright coloring of the syrups allows for some striking visual effects.
The traditional Baltimore-style snowball consists of rather coarsely crushed ice. Some stands sell the "Hawaiian" variety, made of shaved ice instead. Its texture is a good approximation of actual snow. Hawaiian snowballs sometimes go by the alternate moniker "Caribbean." The nomenclature of these shaved ice snowballs seems to depend on the ethnicity of the neighborhood's residents.
Most snowballs go untopped, but the overwhelming favorite with those who do choose to top their snowballs is marshmallow, the viscous stuff that often adorns ice cream sundaes. Chocolate syrup is occasionally used, but it just doesn't seem to work that well.
There used to be a few semi-legitimate snowball stands that would sell you an alcohol-enhanced "X-rated" snowball, but I haven't seen any of those since when I was far too young to buy any but the innocuous "G-rated" cups.