It was the first day of Pop-Up Giant’s weeklong warehouse sale in Winnipeg — and the latest in a growing number of such events. A line of customers snaked through the event centre Sunday.

Theo and Ora Coster designed the original pop-it in the 1970s, but it only became wildly popular in the last two years. (JTA) — If you know any young children or fidgety adults, chances are you ...