My business partner and I started Snow in Seconds (http://snowinseconds.com) on the side, 6 years ago. It is a powder thats been around for decades (used in diapers) but when you get it at just the right grain size it looks, and feels like snow when water is added. We found a good source, designed a professional looking brand, made a TV spot (kinda), bought some search ads, and boom, predictable income.
Sales are online only (have not pursued wholesale yet) and is enough to live off of if all else fails. After 6 years we are have about $600K in total sales.