There are actually companies doing customization in all the niches you mentioned: 1. Textiles: http://www.spoonflower.com http://www.spoonflower.com 2. Clothi

There are actually companies doing customization in all the niches you mentioned: 1. Textiles: http://www.spoonflower.com http://www.spoonflower.com 2. Clothing: http://www.spreadshirt.com http://www.spreadshirt.com 3. Food: http://www.mixmygranola.com http://www.mixmygranola.com 4. Wallpaper: http://www.nakedandangry.com http://www.nakedandangry.com (not true customization, more crowdsourced) Still tons of room for innovation though.