This kind of stuff is common on butterfly-type handlebars:

http://www.componentforce.co.uk/cate...3/foam-sleeves

I don't put credence in horror stories of carpal tunnel syndrome caused by using such material, because so many people use it for touring. For example, my wife used short foam grips on a three-month tour and had no trouble. Butterfly handlebars are usually sold with foam on complete bikes in my country.