Which of Steve Jobss Products Mattered Most

Most inventors and business leaders are lucky if they create one product that changes the way people do things.

Steve Jobs helped create several. Which of his products had the greatest impact on you?

Source:
http://www.nytimes.com/interactive/2011/10/06/business/20111006-steve-jobs-products-poll.html?smid=fb-nytimes&src=ISMR_AP_LO_MST_FB